in my opinion you should stay away from wizzer, suf and anything in hometown square, or new orleans. My personal favorite rides from 8 to 10 at night are Eagle, Iron Wolf, and sometimes V2 and Batman the Ride. Only V2 and Batman on really empty nights though. I usually stick with Eagle.
Also, this is off topic, but do any of you count how many times you've been on each ride at sfgam. Because i have a tally sheet and everyone thinks im insane.