PIAA - bright enough to piss-off everybody on the road, and too expensive for my tastes. I have heard of them melting headlight casings and wiring harnesses from alot of people.
Xenon - Illegal in most cases. I wouldn't use them without the proper projector rigged-up to the existing headlamp, otherwise its glare city, and everyone will hate you.
Silver Stars - Not too expensive, not retardedly bright but a very good upgrade from stock halogens. When I worked at a parts store, I heard nothing but good feedback on these.