Well off the ones playing right now in the NHL.
The only guy that is 5'10 and smaller that is pretty good fighter is Jordin Tootoo
I would of said Mike Brown
as well, but he's just an inch taller.
Aaron Asham would be also up there as well although 5'11" and even though he lost to Brown. I'm sure his next fight he'll give a good showing.
Michael Haley would of been my #1 pick, but he's in AHL.