If you're interested in effective lighting you already use halogen bulbs. Far better than regular incandescent headlights, regular halogens still aren't nearly as bright as High Intensity Discharge (HID) lights. But, they're also nowhere near as costly. A very affordable compromise is the new SilverStar bulb, producing a color temperature very near that of HID lighting.
According to Sylvania, incandescents are at a yellowish 2,800 degrees Kelvin (K), standard halogens at 3,200 degrees K and the SilverStars a bright 4,000 degrees K. By comparison, HID lighting is about 4,200 K and daylight 5,400 K.
Since switching to the SilverStars is as simple as changing bulbs, and at $25 apiece they're a heck of a lot less money than stepping up to HID, the upgrade is both simple and affordable. Only installing a relay (to ensure full battery voltage, especially on older vehicles) or removing any add-on smoked light covers could cost less and still result in a similar increase in brightness. On the flipside, SilverStars supposedly don't last as long as some halogen bulbs, but that's a minor sacrifice if you value good lighting.
We swapped in only one SilverStar bulb at first and the difference from side to side was evident even in full daylight. In the dark, the SilverStar bulb emitted a far whiter and brighter light, as if fed an extra volt or two over the stocker.
It makes perfect sense to have the headlights on our four-wheelers work as effectively as possible, and the SilverStar bulbs are about as good as it gets-darn near HID light, and for pretty cheap.