On the port side of things, there's a well implemented version of Brogue (BrogueX) but it comes with a small price tag which rubs a lot of people the wrong way (it's not ported by the developer, just with their permission, and the original of course is a free game). WazHack also has a brilliant port that runs perfectly on the highest settings on my Galaxy S3 while all but the lowest settings lagged my laptop! That's a paid app though.
If you like Desktop Dungeons style games then Dungeon Ascension is good, it controls well and looks nice (the latest graphical version anyway) but only the lite version is free with the full version carrying a modest price tag. Dungelot is a sort of cross between Desktop Dungeons and Minesweeper and I really enjoy it although I already get the impression it's going to have a shorter interest span than DD; very very nice sprite graphics and a small price tag. 'Ending' is more of a puzzle game than even Dungelot but it's at least a second cousin to roguelikes and is a very well put together game with a simple and satisfying graphical style for those who appreciate monochrome ASCII.
Overall it's still quite an untapped market (ironically) with Cardinal Quest and Pixel Dungeon being the only original, traditional roguelikes out there. I absolutely love the latter though and it seems to be updated every few weeks; best of all though, it's completely free and funnily enough is the one that most warrants paying for (there's a donation option if you want to give financial support).
If any Android devs are listening, a simple touchscreen friendly, visually appealling version of Rogue would be great for short play, the two ports that are currently available are awful. Of course, if you're porting Rogue you'll probably wind up making your own new game based on it and, well, that's what I'd like.
-RiC
