Some new lights like laxdude said, sylvannia silverstars if you want cheap, piaas' if you want more white, and HID's if you have the money.
Changing your turn signals to clear (im currently doing this project)
re-ground your battery
detail your car
maintance
Clean your headlights if they are foggy
upgrade your interior lights (key ring, a/t lights, cluster, a/c control, everything)