Okay, turns out I had a Laser Lens Cleaner from EBGames. I put it in and it span around for a bit, but the CD says wait for the onscreen instructions and they didn't appear (I think it's because it couldn't read the disk)

Another weird thing is, when I listen closely after the Sims CD goes in, it sounds as if it starts up but then something stops it from spinning. Then it tries to start again and after about 1 second it stops again. =/