Larry Bird.
This is the greatest sports frustration to me.
Wish I was born 2-3 years earlier so I could've actually been able to see Bird's prime.
With the exception of Magic's hookshot in the '87 Finals, my earliest recollections of Bird start around '88 or '89. So his body was already breaking down on him and he wasn't quite at the MVP level he once had been.
I saw Jordan's prime so give him the nod but certainly wish I was a couple of years older to remember Bird's.