Meb Keflezighi knows that the Boston Marathon is the pinnacle of all 26.2-mile races because when people meet him and discover he's a long-distance runner, they always ask one thing:
"Have you run the Boston Marathon?" he said. "That's what they tell you. The prestige is there."
Boston -- which comes up again Monday -- is certainly on any list of the premier marathons in the world. But what other races are in the running?
We asked 14 runners -- nine elite athletes such as Keflezighi and five ardent amateurs who have each run more than 100 marathons across the globe -- for their opinions. The two groups tend to look for different things. The elites love the six Abbott World Marathon Majors (Boston, Berlin, Chicago, London, New York and Tokyo) with their prize money, points and competition. The amateurs often just seek new experiences.
"I think it's a great way to see the world, to travel to someplace, do a marathon," said Susan Daley, a 57-year-old Chicagoan who just finished her 500th marathon. "You're with other people that have the sheer passion you have and that connection."
With thousands of marathons around the world each year, picking the 10 best is more art than science. But here they are, in alphabetical order, as selected by our panelist of runners (click here for honorable mentions):
Berlin
Whether you're one of the world's best or a back-of-the-packer, the BMW Berlin Marathon offers a chance for a world record or personal best. It's a flat course with long straightaways, just barely above sea level with generally mild weather. Bands along the course liven the atmosphere. The past six men's world records have been set at Berlin, the most recent by Kenya's Dennis Kimetto (2:02:57) in 2014.
History: Just 286 runners entered the first race in 1974, which covered only West Berlin. The course expanded to the former East Berlin upon unification in 1990. In 2016, more than 41,000 completed the race.
Key feature: On chilly days, runners can get hot tea instead of water at some aid stations.
Scenic highlight: Participants run through the historic Brandenburg Gate near the end of the race.
Quotable: "Beating the world record in 2013 [at Berlin] is something you dream of your entire life," Wilson Kipsang of Kenya said. "When this happened, it was amazing." It was again a year later when countryman Kimetto broke it. "[I] asked my manager, Gerard van de Veen, after finishing if I really ran the world record," Kimetto said. "I did this twice. I couldn't believe it myself."
Boston
First run in 1897, this is the oldest annual marathon in the world and arguably the most prestigious. The field is largely limited to qualifiers, and the qualifying standards are difficult. Boston features a big field (30,741 entrants in 2016) and bigger crowds. "Boston is the grandfather of marathons," said Keflezighi, who won in 2014. "I like Boston because of the tradition. If you are a marathon runner, you are measured based on the Boston Marathon."
History: The first race was 24.5 miles. In 1924, the course conformed to the Olympic distance of 26 miles, 385 yards.
Key feature: Heartbreak Hill gets all the attention, but it's just the last of the four rises of the Newton Hills between the 16th and 21st miles that can test tiring runners.
Scenic highlight: Runners can draw inspiration from the statue of race legend Johnny Kelley at the base of Heartbreak Hill. An old Kelley and a young Kelley are depicted running side by side holding hands. Kelley ran Boston 61 times and won it twice, retiring after the race in 1992.
Quotable: "I ran Boston for the first time in 1979, sight unseen, and I got to the top of the Heartbreak Hills ... I said to the person running next to me, 'So where are these so-called Heartbreak Hills?'" said Joan Benoit Samuelson, who won that year. "And he looked at me like I was half-crazed. He said, 'Lady, you just passed them.' In my training, I do a lot of hills."
Chicago
This October will mark the 40th anniversary of the Bank of America Chicago Marathon, which, like Berlin and London, is flat and fast. Each year, as many as a million spectators line the loop route that begins and ends at Grant Park. More than 37,000 runners started in 2016.
History: Four world records have been set here. In 2001, Catherine Ndereba of Kenya set the women's mark of 2:18:47, which was broken the next year by Paula Radcliffe of Great Britain, at 2:17:18. The men's record has been set twice: by Great Britain's Steve Jones in 1984 (2:08:05) and Morocco's Khalid Khannouchi in 1999 (2:05:42).
Key feature: How flat is the course? There's only about a 30-foot difference between the highest and lowest points.
Scenic highlight: Views of the Chicago River winding through the city are plentiful. Runners cross the river five times.
Quotable: "It's an excellent course, great organization and a vibrant city to race in," Radcliffe said.
London
The Virgin Money London Marathon is not only a great opportunity for elite runners to set records -- world records have fallen four times -- but it's also great for people-watching. Many participants wear costumes. In 2016, more than 30 Guinness World Records were set for fastest times in various get-ups, including the fastest time in a film-character costume (2:39:09 by a man dressed as Elsa from "Frozen") and the fastest two-person three-legged race (3:07:57). A record 39,140 runners finished in 2016.
History: After dueling over the final miles in the 1981 debut race, American Dick Beardsley and Norway's Inge Simonsen -- who had never met before -- decided to cross the finish line hand-in-hand to tie for the victory.
Key feature: With elite fields and a flat course, London races often come down to the wire, so the finish line, with Buckingham Palace in the background, is great for spectators.
Scenic highlight: Runners pass the Cutty Sark, Big Ben, the Tower of London and the London Eye, cross the Tower Bridge and finish near Buckingham Palace.
Quotable: "It's fast, so for a Boston qualifier or for a personal best, that's certainly a place to go to run it," said Deena Kastor, who ran a U.S.-record 2:19:36 at London in 2006. "The weather's almost always perfect ... and paralleling the River Thames and running over the Tower Bridge and running towards Big Ben -- that big, beautiful clock luring you to the finish line -- comes with huge fanfare."
Marine Corps
It's been called "The People's Marathon," as it is the largest marathon in the world that doesn't offer prize money. With its hills and lack of elite field, this isn't a race for records, but it's a favorite for everyday runners. Just under 20,000 finished the race in 2016. The course begins at Arlington National Cemetery, takes a loop through Washington D.C. and finishes at the Marine Corps War Memorial (aka the Iwo Jima Memorial) at the national cemetery.
History: The race began in 1976 as a vehicle to promote the Corps. Uniformed Marines still provide course support. Retired Marine Colonel Al Richmond, 77, has run every race.
Key feature: Teams of elite runners from the Army, Air Force, Marine Corps and Navy compete against one another in the Armed Forces Challenge. In 2016, Army Specialist Samuel Kosgei won the Marine Corps Marathon for the second time in 2:23:53.
Scenic highlight: The so-called Marathon of the Monuments is essentially a tour of the nation's capital. Runners pass all the features on the National Mall.
Quotable: "There is a very emotionally moving 'Blue Mile' segment at Haines Point, which has photos of fallen military men and women, many with spouses and children and most in the prime of their lives," said Jerry Lopez of Whidbey Island, Washington, a retired U.S. Army officer who has run 201 marathons and ultramarathons. "It is a serious statement of the sacrifices often required to keep our freedoms."
New York City
The TCS New York City Marathon has the bridges, the five boroughs, the huge crowds and the elite fields. Plus, it's a challenging course for as many as 50,000 finishers each year. "It's truly an experience to race a marathon there and take in the unique atmosphere in each of the boroughs and the way the entire city comes out to celebrate with the runners," said Great Britain's Paula Radcliffe, who has won three times.
History: The race began in 1970 with loops around Central Park but evolved in 1976 into the full-city, five-borough run it is today.
Key feature: Just after the halfway point, runners climb to cross the spectator-less Queensboro Bridge into Manhattan. After crossing, they get a boost heading downhill on First Avenue to the cheers of thousands lining the course.
Scenic highlight: The race begins with runners charging over the Verrazano-Narrows Bridge from Staten Island to Brooklyn, with views of New York Harbor and Manhattan in the distance.
Quotable: "Everything about New York I love," said Tatyana McFadden, the U.S. wheelchair standout who has won the race five times. "I think they are the best organization. They do a wonderful job. And I love to climb. I love to climb hills, so that's a really strong race for me."
Olympic
It is only every four years, the venues change, and the race is for only elites, but the fields are the best, and the chance to make history is unmatched.
History: It began in Greece in 1896, from the village of Marathon to Athens, with Spyros Louis, a Greek shepherd, the winner. The barefoot Abebe Bikila of Ethiopia won at Rome in 1960. The men's race has been won by Africans eight times, including five of the past six. The women's race was added in 1984, with Benoit Samuelson winning.
Key feature: In 2004, the race was again run in Athens, with Americans Keflezighi taking silver and Kastor bronze.
Scenic highlight: Watching the lead runner enter the Olympic stadium for the final push toward gold.
Quotable: "Running that historic route from Marathon into Athens and finishing in Panathenaic Stadium was incredible," Kastor said. "It was really spiritual."
Paris
The Schneider Electric Marathon de Paris is huge, attracting more than 40,000 runners from about 150 nations in 2016. It isn't as fast as Chicago, Berlin or London, yet Kenenisa Bekele of Ethiopia ran a 2:05:04 in 2014 to set the course record. It's also a race in which costumes are prevalent and runners enjoy themselves.
History: The first marathon in Paris was run in 1896, but the modern version began in 1976.
Key feature: In order to participate, runners must provide a note to race organizers from their doctors declaring that they are healthy enough to run 26.2 miles.
Scenic highlight: It's a travelogue, with the course winding past the Seine, the Eiffel Tower and cathedral of Notre Dame. It begins on the Champs-Elysees and ends near the Arc de Triomphe.
Quotable: "I went there to enjoy it," said Kevin Brosi of Dallas, who has logged 443 marathons. "Lots of costumes, lots of enthusiasm, lots of sights. It was just fun. So many people having a great time. ... You can tell by the faces of the people how great a time they were having."
Rome
It's a spring race with generally mild temperatures through one of the world's great cities. Although Rome is known for its hills, the marathon course is generally flat. One challenge can be some narrow, cobblestone streets. The race starts and ends near the ancient Colosseum. More than 13,300 runners from across the globe finished this year's race.
History: The race, which began in 1982, has been dominated in recent years by African men (12 straight wins) and women (nine straight).
Key feature: Costumed Roman Legionaries salute runners at the finish and clang their shields with their spears or swords for encouragement.
Scenic highlight: The route passes landmarks such as the Trevi Fountain, Saint Peter's Basilica, the Vatican, the Spanish steps and the Piazza Venezia. Live music is played at several points along the route.
Quotable: "Enthusiastic Italians continually shout 'Bravo!' to lift your tiring spirit" along the route, Lopez said.
Tokyo
It's a relatively new race, begun in 2007, and one that's flat (just 129 feet of elevation change between the lowest and highest points) and attractive to elite runners. It's also popular. About 300,000 applications were received for this year's race, which was limited to 36,000 (with most chosen by lottery). More than 1.5 million spectators turn out each year. The course will be part of the Olympics in 2020.
History: Since its start, the race has produced fast times. Kipsang (2:03:58) and fellow Kenyan Sarah Chepchirchir (2:19:47) set course records this year.
Key feature: The route has recently been made even flatter by eliminating some bridges (and their inclines) that impacted tired runners late in the race.
Scenic highlight: This year's course was changed to give runners more of a "wow" finish in front of the grounds of the Imperial Palace.
Quotable: "It was only the second time foreign wheelchair racers were invited this year," said South African Ernst van Dyk, who finished ninth in 2017 and second last year (and has won Boston 10 times). "Very fast course with super nice surface. Potentially our marathon wheelchair world record could fall at this one."