Doesn't mean Shaq had the greatest career, but his peak was better than anyone else's.
In Shaq's best year, he put up 29.7 points and 13.6 rebounds. As dominant and great as he was, I don't think that matches up to Wilt's or Kareem's best seasons. I mean, it's easy to discount Wilt due to his era, but 50.4 points and 25.7 rebounds is hard to minimize.
If we're talking just pure statistics, sure. Wilt trumps them all, but I don't think anyone has him as their overall 'best'. And I do discount his stats due to era somewhat. He had almost no competition. The one player who could truly match him, Russell, never allowed him those kinds of averages. Wilt would never get those averages in today's NBA. I think Kareem could come really close to matching Shaq, mainly because Shaq would have a hard time with Kareem's skill (he could pass too). The sky hook will forever be the most unstoppable shot in basketball.
I don't know if we'll ever see a player of Shaq's combination size, athleticism, and agility ever again. It's a shame he wasn't more dedicated, the debate would be moot.
You are wrong on Wilt. Wilt dominated Bill head to head. In fact he was generally above his averages against Bill. Bill just had vastly superior teammates for much of their time.
No doubt Wilt was a physically gifted player (similar to Lebron in that respect), but he was also a very good overall player. He had all the skills and he never came out of the game. He averaged 48.5 minutes one year. He ran up and down the court all game long and just didn't quit. Sure he was tall, but he was in incredible shape and was stronger than anyone else in the league by a very wide margin (contrary to popular belief, he was not the only 7'er in the league and was often not the tallest player in the league). His coach asked him to score, so he did. His coach asked him to pass, so he led the league in assists. Yes he was prickly to deal with at times and clashed with some of his coaches, but very few of the all time greats didn't (I mean look at Jordan).
Wilt Chamberlain is the greatest player to ever play the game.