It's hard to pick one...
Cooper Cronk is up there though, I can't help but admire him as a player, and I never see him bitch and moan. Ultimate professional.
Big fan of Slater too, but he hasn't played for a long time, so I don't know if he counts right now.
Some other players I like
Marin Taupau
Josh Reynolds - Love him or hate him, I simply enjoy watching him play. The type of player who gives 110%
Blake Austin - Same reason as Reynolds but less of a dick
James Graham - Love what he brings to his team
Robbie Farah - He punched Anthony Watts so he'll always be up there
Josh Mansour - Fun to watch
Radrara before all the shit - Same as above
Tedesco - Raw talent
Jason Taumolololo - absolute machine
There's a few more I could add to the list but that'll do.