I always enjoy a little movie trivia. Box Office Smash is a pretty good trivia game, with a variety of different questions. There are scrambled movie titles, movie clips (where you answer questions about the movie you just saw), lists of movies that you have to rank in order of release, etc, etc. This is the sequel to another 360 game I actually own, and I've only played that one a handful of times. If you're not playing with a group of friends, there's something hollow about the experience.
Achievements unlocked? A metric ton, all in a couple of hours. I think this is the highest number of achievements yet for me on this challenge (on a single game in one day):