Michael Vick isn't bad either....
Ugh... dude, where do you get your "Greatest Athlete of All Time" criteria?
First of all, "greatest athlete" is so generic and subjective... there so many different criteria and skills necessary to be an athlete. Someone who many be considered a great athlete because they've trained exhuastively their whole life, maybe be a different kind of athlete than one that was born with a particular skill, ability or body time.
Then you have your different sports; we think of athletes almost exclusively as basketball, baseball, football and hockey players, with a little bit of Olympic type things mixed it. But athleticism isn't really something that can be measured.
For instance, Jim Thorpe... he was an unbelievable athlete in its purest sense; that is, he certainly wasn't the greatest as far as athletic ability. He's often cited as the most versatile athlete of all time; and compared to Bo Jackson's mediocre numbers in just baseball and football, I'd say Thorpe deserves at least consideration; but more of versatility than unadulterated athletic ability.
Another guy most of you are forgetting is Muhammad Ali, who was named as the greatest athlete of the 20th century. He really was an unstoppable boxer, and to think that he went to toe to toe in fights with, arguable, the greatest generation of boxers of all time.
Michael Johnson holds some impressive running world records; and Sergei Bubka has a pretty impressive pole vault record.
You see, it's impossible to say, and this entire "who is the greatest athlete of all time" discussion has turned in to "who is your favorite athlete from the last 3 years."