AC/DC - Just love how the theme integrates into the game and it has one of the best rulesets out there. So many different ways to attack the game, so many things to do, so much balance with shots. Game I always find new ways to play and never get tired of.
Simpsons Party Pinball - I mainly love the theme but the rules are really deep and there is a ton of fun stuff to do. Just a great overall game that reminds me a lot of the great 90's B/W games.
Sopranos - Probably because I played it a ton in college at a bar but I really enjoy this game. Wasn't even a Sopranos fan but the theme works well and the game is perfect for casual enjoyment.
Honorable mention goes to RBION. Like a poor man's TZ with a lot of fun stuff to do.