None of Pac's combos are really guaranteed, but there's a lot of stuff that works as long as you can keep an eye on what your opponent's doing.
The "combos" that immediately come to mind for me, and that seem to work pretty frequently, are:
- Fair, when you're moving forward at the right angle, can combo pretty easily into another quick Fair or even a Nair.
- At low to mid percents, a forward throw lines the opponent up perfectly for a key.
- At low percents, a down throw can often be followed up by an immediate dash attack. If you're feeling particularly thirsty, you can jump up and try to hit your opponent with an up-air. He or she has time to airdodge to avoid this, though, so try mixing up your moves (Nair or Dair, for example, can punish this when used right.)
- Speaking of which, Pac's up-air has great range, and it's not hard to hit someone twice with it if you time it right. If you can slam someone with a grab to down-throw to dash attack to up-air to up-air combo, you'll look and feel incredibly stylish!
- Oh, and Pac's up-tilt can hit two to three times in a row at very low percents, but good luck hitting it. Pac-Man isn't Mario.
Well, that's all I have to offer right now. Hope that helps, and happy repeated chomping!