Cal Ripken Jr. immediately comes to mind, for all of the reasons everyone already listed.
I agree that Derek Jeter is a class act, even if I don't like the Yankees, I do respect Jeter a lot.
And, as a Rangers fan, I have to say that I totally think Michael Young is a class act; he never argues with umps, he plays hard, and he respects his teammates, coaches, manager, and opponents. =D
Btw, I can't believe Ian could be out for the rest of the season!!! (Sports hernia, I think.) Aaah!!! I'm so sad... =(
First CJ... Then Murphy... Now Ian! T.T