Might and Magic: Clash of Heroes - this game is pretty awesome so far. I can't be 100% certain but the battle system seems unique to me. I like it.
I picked this one up awhile ago after playing the trial game. It's pretty good. I can see where it would be addictive. Solid turn-based strategy.
Dead Island. So far so good.
Hit me up if you're online and want to play co-op. I'm pretty far into it, but I'd be glad to drop in and help out.
How does it compare to L4D and/or DeadRising?
I liked bits of both but overall couldn't get into either of them.
Dead Island is a blast! It's open world, but there's missions that you need to go on to develop the story, with an abundance of side quests to get you cool weapons, mods, xp, and cash. There's skill trees (making it RPG-lite) and weapon crafting/repairing (TONS of stuff to make...and finding the ingredients to do so is a nice sub-theme personal challenge) as well.
The zombies are not as brutal and fast as they are in L4D; and there's no psychotic "director" dictating the action like what Valve put into L4D based on your skill level of play. The Dead Island zombies are tough, though, but killing them is VERY satisfying.
The best way to describe Dead Island is that the overall story and atmosphere feels like a Far Cry game (because it's very open-world and you do use vehicles and guns), crossed with Fallout 3 (weapon crafting system), Borderlands (skill tree mechanic) and Dead Rising 1 & 2 (you can use tons of different things as weapons), but with zombies of variable speeed and toughness to provide a significant challenge. It's a VERY underrated game!