Shinkuu... Bumpdoken! This thread really needs to live on.
I've spent the last couple of months addicted to a couple of indie games. One of them's FTL, which is hardly overlooked (but is still worth mentioning, as it's simply amazing), but more recently I've discovered, bought, and got hopelessly addicted to Desktop Dungeons. It's been mentioned already, and it's in beta status yet, but you can get the Alpha to check the kind of gameplay it has. Like with FTL, there really isn't anything like that out there.
Any other unconventional/genre mashup roguelike-likes? I already know and love Spelunky.
It's now mid-March; it's depressing that this hasn't got a single bump since my February one! I'm tempted to break the no double-post rule to bump it... at the very least, I linked it from my "essential indie games" thread. :/