My vote would be for Carceri (though I seem to be the only one), because I always thought the atmosphere\setting for that game sounded pretty cool. Plus it would be interesting to see a traditional-dungeon-crawl (though it sounded like it was more than that as well) kind-of roguelike from someone who has usually programs anything but :)
Also I'd really like to see the graphical version of DoomRL.
For that matter I'd really like to see GenRogue.
And bererk and diabloRl are pretty cool, and whatever your next crazy idea is , I bet that'd be cool too...so, um, basically do whatever you like :)