Kos has grown on me since his last effort---
GSP, Machida, Randy,
Spencer Fisher (he always spills his heart in every fight),
Tyson Griffin, Forest Griffin, Clay Guida, Hendo, Wandy, Roger Huerta, Both Noguieras, Diego Sanchez, Joe Stevenson, Jens Pulver, few more--- BUT those are the first ones that come to mind.
Of the OL-timers--- the Gracies first fight I ever watched was a Royce Gracie fight.
Win or loose I always root for the guy that just puts everything he has into it everything he has got.