MLB has the best game as far as how it reflects the quality of the sport, but the worst skills competition.
the NHL and the NBA all star games themselves are about the same as far as entrainment goes. I don't watch either.
I'd say the NHL has the best skils competition if you're looking at the whole event.
While i enjoy(ed) the slam dunk contest and the 3 point contest, the way the NBA has chosen to judge and present the slam dunk contest has totally ruined it for me. The event has become a total mockery thus i hate it and won't bother with it anymore.