I prefer the classical definition of roguelike, though I prefer them to be more simple and less hardcore (ie. not so nethack) and with that in mind, I would say mobile games like Quest of Dungeons, Cardinal Quest, Pixel Dungeon, Sword of Fargoal, 100 Rogues, etc... I enjoy playing.
Outside of that classical scope, I enjoyed Weird Worlds and Out There.
I would love to see a genuinely solid Nethack port to iPad. Not a "like Nethack" but the actual game backed by the wiki, with sane tablet-focused controls. There are a couple quickie basic ports but I haven't really seen Nethack (or Angband) in all its glory.
Of course I'm posting this in the hope that someone will say "doffus, check out _____"