Spell Tower - iPhone - I don't know why, but this game is wonderful. I am a huge fan of Scrabble/word games, though, so be forewarned. If you've ever played the timed modes in word games (aka Scrabble Blast), this game is a distant variation, but with very nice incentives to create sophisticated words (timed games tend to reward *any* word completed, even a long sequence of short 3-letter words. Spell Tower, however, forces you to create longer words as part of your core strategy: you gotta eliminate "black holes" and bonus tiles with strategically-placed, longer words).
ONE CAVEAT: This would be a perfect game, but the touch response needs to be tweaked. When crucial moves need to be performed before time runs out (mere milliseconds for me since I'm often digging myself out of a hole), I don't want to worry about the proper sequence of letters registering. I've never had this problem with an iOS game before...I hate to say it, but this game reminds me of some Android 2.3 games I've played (where the touch response was just slightly *off*). Anyway, I hope that the developer tweaks this. Then I will be in absolute heaven. Even with this flaw, this game still captivates me and is well-worth playing.