From my perspective based on my own athleticism, gymnastics would be the most difficult for me and I think for most individuals to execute even at the most basic level. I'm not saying that we would be good at the majority of the other sports but most people could learn to row a boat or swim the breaststroke for example. Compare that to the pommel horse, balance beam, vault or rings. The learning curve and the combination of speed, strength, coordination, finesse, timing, pure born gymnastic athleticism would be too much for large majority of people to even execute a basic move of that particular gymnastic event. I'm totally blown away by the athletes on the rings. I'm amazed at the stress the upper body (tendons) can take with that event.
Just for fun, water polo would kick my ass too.
I'm in the minority that actually likes the summer olympics better than the winter.
