Amnesia is good for its genre i'd say. Although considering your only defence from the monsters is to run and hide, it's not popular amongst those who prefer shooters. And it's hella scary.

Devil May Cry 4... Well I found it a lot more "active" and fun than Devil May Cry 3 was (not that I didn't enjoy DMC3). It seems more action-oriented with a side order of minor RPG elements and a few puzzles.

Also Mirror's Edge was great fun and a good example of "short but sweet".