Sly 2: Band of Thieves
I actually tried to start playing this some months ago, and unfortunately I can't really muster up the interest to get back into it. The new formula I saw in the early game is really cool, having more in common with Assassin's Creed than with the first Sly Cooper -- rather than discrete stages, the medium-scale "heist" takes place in an open area which also consists of sub-objectives and collectibles. The overall structure seems pretty great, plus the game also appears to have addressed most of my mechanical complaints about its progenitor. But the controls, in particular the camera controls, are just too awkward.
Which is a shame, because in 2004 this was probably perfectly adequate. I've just completely missed the boat on this one. Sorry Sly.
Progress: Gave Up