There are more than a few out there-
There is HID (way expensive), H4 conversions (under $100), and plain ol' halogens.
I upgraded to H4 light bulb and housing systems. It consists of a lense that looks like the original bulb with an opening and retainers in the back of it to secure an H4 bulb. I did all four head lamps.
The lenses run $20-30 each. The bulbs run about $8-15 for a pair. I went with all four bulbs. I purchaesd four Hi/Lo beam bulbs and then cut of the center pin on two of them so they would fit in the high beam harness.
THEY ARE EXTREMELY BRIGHT! In fact, when you look at the lights from about three feet away you see a line shaped filament. It doesn't look like your regular lights, seeing as they are brighter and the fact the OEM stuff never had a bright horizontal line eminating light. It stll keeps the stock look in terms of the lense appearance.