HID headlight conversion. Kind of expensive (quite expensive for headlights comparatively to regular halogen) but I think worth it. It is like day all the time in front of my truck. I wouldn't buy another vehicle without them. The conversion kit with the first 2 bulbs was $300 (you can get them now for $200). The bulbs last 3-4 times longer than halogen bulbs, produce a brighter light and use less energy. Best of all they look cool!