I installed the HIR9012 bulbs the other day and they are a HUGE improvement.
I had Sylvania Silverstars before and these are way better. Plus they are supposed to last 1000hrs instead of 250hrs. You have to modify them with a dremel but it only took me about 5 mins. They are expensive but I think they are definitely worth it. I got them from Daniel Stern for $34us each.