So many bulbs, so many choices...LED, Low voltage, halogen, incandescent. Let me explain.
Incandescent: Regular light bulb still renders (at 2500K) the best in terms of quality of light. It is however, really bad with 10% efficiency, 7 month life and 300 degree heat emission.
Halogen: Halogen is an incandescent bulb with halogen gas on the filament. It is a whiter beam, which is desirable in kitchens (2700-3000 Kelvin), but it is an incandescent so it is generally an inefficient bulb.
Low Voltage: Low voltage is another incandescent white light. The light and the beam can be controlled more readily, because it is converted to 12 volt from 120. Although there are a few high quality low voltage bulbs with life of up to 18,000 hours it has the characteristics of the aforementioned bad incandescent light.
CFC: Compact fluorescent bulbs have a better longevity at 7 years with less heat emission. You can buy dimmable, color rendering fluorescent bulbs, but typically a basic fluorescent cannot do either.
LED: Light emitting diodes (LED) are the best with a 20 year life, zero heat emission and 90% efficiency. It even renders similarly to an incandescent. Payback is 2.5 years, but the initial outlay is expensive. Be VERY careful with LED lights: buy them with a CREE chip, so the quality of the light is good.
This post is somewhat complicated, but search LED and Kelvin posts for a better understanding
BTW, thank you to Christine from Canton...appreciate the Twitter mention.