Try something new. If I had a spare $50, I'd get some primer, some paints, and a couple of miniatures and give painting a shot. This of course is assuming that you don't already do that.
Seriously, if you want something different pick up a new game. All Flesh Must Be Eaten is one of my current favorites. Essentially Resident Evil or Dawn of the Dead in a roleplaying game. Lots of fun, good for a long campaign or a short term one. Easy system. And it has d20 modern conversions, so if you want you could have your D&D world become overrun with zombies. Especially if you pick up the upcoming Dungeons and Zombies sourcebook that does AFMBE in fantasy.