Rails, one area you out, and which I believe Tarek had mentioned in the past, but I thought HD's term of athletisicm included strength, and can be included in the broad real life definition of athleticism.
I think of a kid like Aaron Grey at Pitt and whereever he's at now in the NBA. He was never a great "pure athlete" nor super quick, but he was a bull.
Additionally, I don't think any 1 particular sport would settle the debate over who's the best athlete. So many different sports require different aspects to compete at the top level. A athlete in Golf uses much different skills than a top tennis play, which both use different skills than a top football player, which is different than a 100 meter champion, etc...
At first blush, I agree that the top SG or SF in the NBA would be amongst the greatest athletes, but then thinking more, I wonder if a top LT in football wouldn't fall under the same lines, but add in more strength into the occasion. Both have to use a relative amount of speed to get from A to B, both need great flexability, great change of direction skills, hand-eye coordination, etc.... It would be great to see a "battle of the stars" type event that the athletes were there to truely win the prize, rather than get some TV time and have fun. Test 'em in straight line speed in a 200, some sort of jumping skill, some sort of lateral quickness, strength testing, endurance, hand-eye coordination, etc..