You know marathon triathletes were one of my first thoughts but I don't think I would say they are the best athletes. Being the most fit doesn't make you the most skillful. There are and having been many amazingly skillful athletes that have also been in phenomenal shape.
Here are 10 I thought of for top athletes in the world currently and of all time. I will follow up and put them in order and possibly add or subtract if I think of someone I left out.
1.Manny Pacquiao (boxers are extremely fit and well conditioned strength and endurance/cardio wise. Manny has held so many titles in so many different weight classes its unheard of. I don't know if there will ever be a Pacquiao vs Mayweather fight but I wish it was 5 years ago when they were at their best.
2.Lebron James (NBA basketball) (just like Mayweather gets mention Kobe gets mention as well) Lebron is incredibly strong, fit, fast, and we conditioned. He not only can score at will, in many ways, power dunking over everyone, or super long 3-pointers. He does it all, he is a great defender, blocks and rebounds well, steals, and is an excellent passer who completes a large amount of assists.
3.Roxrite (Neguin gets mention) Bboys are to me at the top of athleticism. Timing, strength, flexibility, style, conditioning the best are doing things with the body that no one else can and that often times doesn't even look real.
4.Anderson Silva (MMA Middle weight champion)(9 title defenses)(Georges st-pierre mentioned)
5.Aaron Rogers (NFL quarterbacks) (Drew Brees gets mention)
6.Leo Messi acceptably regarded around the world as the best soccer player on the planet, and soccer is the most played and watched sport in the world. (Christiano Ronaldo gets mention)
7.Jordyn Wieber (female) (Kohei Uchimura (male)) Gymnists are among the top athletes in the world no contest.
8.Calvin Johnson (NFL's best wide receiver) (Greg Jennings gets mentioned)
9. TIE Daniel Sedin (NHL) (Hockey) AND Rafael Nadal (Tennis)
10.TIE Javier Gomez (triathlete) AND Serena Williams (Tennis) Currently #5 but the year still has a lot of the big tournaments to play and she is still the best).
Its a very controversial list I know, but its a very hard category to fairly judge. Just to point out THERE ARE NO CRICKET PLAYERS ON MY LIST....no baseball players either sorry baseball heads some of them are very talents but we are talking over all athletes...No golfers either sorry Tiger..
Lol this list is awful (no hate), first off Usain Bolt being the fastest athlete in the world deserves some love, secondly Brian Clay should be on here considering he's the best decathlete and thirdly where's Michael Phelps? Clearly from an American point of view haha
(full disclosure: I'm American as well)