Your list does not have to be your 5 fastest, just your personal faves. Mine:
1. Boston Marathon. The biggie. And a tough course. Ultimately thrilling when you come down Boylston Street--knowing you conquered not only the distance, but the quad-eating downhills and the monster Newton inclines that culminate with Heartbreak Hill. Also great to meet runners from all over the world who worked their tails off to qualify for Boston.
2. Miami Marathon. My PR in my prime running days. The heat and humidity are not for everyone. But the palm trees and beautiful scenery of Miami, Miami Beach and Coconut Grove are utterly breathtaking.
3. Berlin Marathon. My lone Europe race was a wonderful experience. So flat it makes Chicago look hilly. And inspiration from the Victory Column at the start and the Brandenburg Gate at the end.
4. Marine Corps Marathon. My father and uncle were Marines, so I was honored to run in their memory while also wanting to honor the military in general. Humbled to have been aided by the Marines. Mostly flat course, with a killer hill at the end as you reach the statue of Iwo Gima.
5. L.A. Marathon. I ran the Stadium to the Sea course in February 2016...they have had a few course changes before and after. Sweet sights along the way--Dodger Stadium, Disney Hall, Hollywood and Vine, Troubadour, Beverly Hills, Santa Monica Pier.
Realizing that my 5 faves were all big city marathons, I will list some small town marathons with nice courses and kind people: Brookings (SD) Marathon, Eisenhower Marathon (Abilene, KS), Mill Race Marathon (Columbus, IN).