So I dropped 5 bucks to see what all the hate is about for Dungeons of Dredmor.. And yeah, I can kinda agree that this 'roguelike' shouldn't be outvoting something so well established like Crawl. The UI's pretty crappy; trying to go through the menus to craft is a pain in the ass, and so is the inventory management. The reliance on the mouse is annoying. For example, you have to click on items to pick them up if you didn't set up autoloot ie no 'g'rab button like Crawl. Map is nearly indecipherable and hard to see. Your starting skills (you can choose 7) pretty much determine what your character will be for the rest of the game; no branching out later like Crawl, and no crafting if you don't have the appropriate crafting skill (although you can craft a few basic things with 0 crafting skill.) No diagonal movement (heretics!) means you can find any old one tile corridor and comfortably take on a whole group of enemies one by one (ranged attacks can still get you though.) And I found myself missing the ctrl+f functionality of Crawl; very hard to remember where things were after you leave a room for awhile.
Despite all of these downfalls, I found DoD to be fairly fun, and a relaxing change of pace from the oft intense difficulty of Crawl. There are some interesting mechanics in the game, like dual wielding, counterattacks, and 'haywire' which is basically critical hits for spells. Monster Zoos are a nice surprise (think of those vaults in Crawl where it's just a room full of bees/kobolds/orcs/etc) and satisfying to clear. Descriptions are written in a funny, light-hearted manner like Crawl. There's even a god you can sacrifice Lutefisk to for some sweet artifacts
. Monsters like the diggle and blobby make an adorable sound when they die ^^. And hey, the popularity of Dredmor with the mainstream crowd means more interest in roguelikes and more potential converts for Crawl.
Overall, I can recommend at least trying out Dredmor, especially for a measly 5 dollars which is probably less than the cost of a decent lunch. Just try not to compare it to Crawl too much because it won't live up to that expectation; instead, think of Dredmor as more Diablo-ish than roguelike-ish. Oh yeah, and take my little review here with a grain of salt because I've only made it to Dungeon level 3 so far