To me the definition of toughness should be the player who looks for body contact. Who else is there? Bynum on the Pistons is a tough little guy.
you mean in general or over 6'5? (if so we should do a sister thread)
some guys who are out for contact, any height- (note that im not saying there tough, some of these guys are floppers, just who is looking for it)
Parker, Pierce, Granger, lebron, manu, stucky, bynum, amare, josh smith, rondo, G.wallace, iverson, TJ ford, wade.
I know im missing some, but those are some of the guys that play that way. not really in any order, and some (pierce) do it at a high level and finsh while others (manu) are just looking for the foul.