I think Sir Joseph has to be in the running for this award as he was so 'committed' he took it off the pitch too, ehehe, but then there are so many players going back, most of whom have already won a mention in this thread.
Paul Stewart would chase down and hustle defenders, and put himself about (and was a big favourite of mine) - I'm not sure if he's had a vote yet.
Joe Corrigan came through a very rough early patch with City to become a big fan favourite, so plaudits to him too.
(with more recently Tevez - always harrying for everything, who I don't think has been named yet)
- a very tough question to answer really, especially because the best 'triers' are often the best players too. Strange that isn't it?