I've been dreading this particular poll. There is no good answer.
Ultimately, I went with Mason. He has only had one good year, but that is as many as any other goaltender has had. And his good year is much better than any other goalie's good year, so, Mason wins, but with an asterisk.
Tugnutt played pretty good for us the two seasons we had him, but his numbers weren't that impressive. I gotta go with Mason based on last year alone. I know Tugnutt was a fan favorite back then but I'm not 100% sure but I think his career save percentage is below 90. So I gotta go with the guy who almost by himself took us to the playoffs last year. If Brathwaite(sp) were in this pool I'd have chosen him!
So, in terms of best seasons overall, it comes down to Leclaire in 2007/2008 and Mason in 2008/2009. I'd probably give the nod to Mason, even though Leclaire had less of a team to work with. (Leclaire's Sv% and GAA were actually better than Mason's, just not better relative to the rest of the league, and he had one fewer shutout in his best season.)
Body of work, you have to give to Denis or Leclaire.