Bruce Lee .....
Newell is a huge inspiration!
Tom Sauer - fought with turrets syndrome and became a champion!
(Mr Sauer said he never felt more comfortable or at peace than when he was in a ring or cage. (something to that effect) It is beautiful, and amazing how once he steps into the ring/cage, all signs of his syndrome seem to disappear!)
Jens Pulver - Over came abuse as a child and became a World champion (he and his family were victims of domestic abuse / Jen's dad stuck a loaded gun in Jens mouth)
Yuki Naki - Blinded in one eye during a nhb tournament fought two more fights that same night - kept this a secrest to not tarnish the image of the sport
Enson. Hella tough dude. His mentality was inspiring
Boxing: Joe Louis, Ali & Tyson
MMA: Fedor, Saku, & Wand (fuck I miss Pride)
Kickboxing: Andy Hug, Peter Aerts, & Buakaw
Let's not forget Daniel Larusso.
I odn't know exactly what inspirational means, but in terms of a fighter who made you make changes, it is Royce Gracie, and no is close or ever will be.