Mass Effect 3, or the Leviathin DLC?
I love ME3, except the following:
The ending is crap.(Although they do have a DLC that expands on it and makes it MUCH better from what I've seen. I haven't actually gotten it myself though.
The only way to get your readiness rating above 50% is to do online MP. And the readiness you DO gain, drops 1% every day you do not play MP. (To a minimum of 50%) which means the best a non-MP person can do is something like 3800-ish effective military strength, while you need around 5000 for the "Best" endings.
Those were my only real complainst about it. The game is awesome while you're actually playing it, right up till the VERY last portion, after your last battle.
-Twi /)