I'm sure there are, but I don't do LANs, so I don't really listen for them. My friend mentioned that they have FPS LAN parties at UM Flint every........2 weeks or something? But I think a big party's CS. Sorry that I'm not of much help, but I'm sure you can find some.
If you're around AA, the League Underground opened a new Cybercafe-ish place, with about 10-15 PCs and 6-10 Macs (don't quite remember) all installed with the latest games. Plus, i saw a flyer yesterday with a new place on the second floor, somewhere by the State St Starbucks.
Good luck. 🙂