Since the government has banned most sales of incandescent lightbulbs, newer technologies like CFL (Compact Fluorescent) and LED lights have taken its place. There are plenty of reasons not to like CFL, though. The light they produce is harsh, they contain Mercury so there are pollution issues, and they take time to "warm up" after being turned on. LED bulbs, on the other hand, take very little power and last for a very long time. The only issue with LED lightbulbs at this point is the heat they produce, requiring a large and expensive heat sink to be used.
The sale of incandescent lightbulbs is now against federal law. Incandescent bulbs are very inefficient, don't last very long, and compact fluorescents have mostly taken over the market. Now LED lightbulbs are finding their way into stores. The big problem with LED lightbulbs is the heat that LED lights generate. The other issue is color, since they don't produce the warm glow that the incandescents do. LED lights from Philips are in the form of a disc instead of a traditional bulb, which can dissipate heat better.