I'm already pre-reg'd for this year again

. Been going to Fanime ever since I came up here for college in '03 (2004 was my first). Definitely be looking for me around the convention and at the Yaoi Con events, of course

.
Things to do...gonna have to second Gothkitti on Re

eath. Re

eath is just shear AWESOME. I watch it every time to go to Fanime. Plus if you really liked it, you should try and catch their other fandub, Nescaflowne (battling coffee companies using Escalowne) and Fanboy Bebop. And I'm so jealous, Gothkitti! You went to college with them!
Wandering and talking to other attendees is also fun
If you cosplay or like taking pictures of cosplayers, don't forget to check out the Fanime forums in the Cosplay section for the Gatherings. That's where people plan for cosplayers of the same series to gather up and take all sorts of pictures in tons of poses at. It makes for some great action shots.
Oh, and also getting food with other people (especially cosplayers) is a blast. Almost everyone goes for food off-site (lots of places to choose from within walking distance). It's always fun seeing cosplayers invading the 'normal' people as they eat, lol.