My favorite NBA athlete is Hakeem Olajuwon or Tim Duncan.
They are 2 of the best Bigmen in my opinion.
Duncan is the pinnacle of fundamentals, teamwork, & longevity. I love watching him and I have based my game off of him since he's so effective and hard to stop. I just love the way he plays and he plays with passion yet he keeps calm at all times. He's truly one of a kind.
As for Hakeem, he grew up with nothing and still became the staple of what a finesse Bigman should be and play like. He was truly an amazing player and he is in the top 10 for steals..as a damn near 7foot player. That's enough of an accomplishment in its own. I never got to watch him play live, but I have watched countless hours of him playing via YouTube and I still to this day can't fathom how he was so agile and remarkable as a player.
As for the NFL, my favorite player would have to be Ray Lewis, Brian Urlacher, or Dick Butkus.
They all were amazing Linebackers in their own respective careers, never backed down from anything, and always gave 100% while playing with grit and pure passion. I always tried to play like them when I played football, even though I played LE. If you play like them, you will always do good no matter the position.
I'm not a big fan of any other sports besides Boxing and MMA, so I don't want to go into too much detail about those sports and my favorite ayers in said sports.