Whatever looks best to me. BBS is the safest bet for any car, I've noticed, but there are some car/wheel combos that look hideous. For example, I usually don't like colored rims. So The Denso Sard and Castrol NSX have different wheels on them; this way, if I win them as prize cars again and again, I don't accidently sell them...which I've done once before (oops!)
If a car has 3-spoke rims, then I usually find something else for it, too. They make cars look like toys, in my opinion. An exception to the rule is my RX-7 GTC LM edition, I swapped the stock wheels for the black and blue Yokohama 3-spoke wheels; you can't see any spokes when it's fitted to the car; it looks like a spoke-less wheel with a matching rim which looks rather neat to me.