Here's a rundown on your main choices for bulbs.
• CFLs: or compact fluorescent light bulbs, are sometimes called twisty or spiral bulbs. The earliest bulbs turned people off with their little light and slowness to come on, but they now come on instantly and produce a light quality equal to incandescent.
Pluses: They're fairly cheap, about $1.25 to $2.50 each for a 60-watt-equivalent bulb. They last a long time, about nine years with normal use. They burn cooler than traditional incandescent bulbs and use much less energy.
Minuses: They can take a minute or more to reach full brightness, so they're not the best choice for stairways or other places where instant brightness is important. Some CFLs can't be used outdoors, in enclosed fixtures or with dimmers. And CFLs contain mercury, albeit a tiny amount.
• LED: These bulbs, illuminated by light-emitting diodes, until recently were pretty much limited, but recent improvements in price and quality make them worth a look.
Pluses: They last so long you may never have to replace them. Energy Star LED lights are guaranteed to last 25,000 hours, which translates to almost 23 years with normal use. They're also slightly more energy-efficient than CFLs, using 10 watts of electricity to produce the light of an old-style 60-watt bulb. What's more, they're cool to the touch.
Minuses: They're still fairly expensive. You can find some bulbs for $10, but brighter bulbs are still in the $30 to $40 range.
• Halogen bulbs: Really a type of incandescent bulb, except the filament is enclosed in a capsule filled with halogen gas under high pressure, allowing the filament to burn hotter with less energy, making the bulb more efficient.
Pluses: They look and perform pretty much the same as old-style incandescent bulbs, but with less electricity. They come on instantly, can be dimmed, produce a familiar warm light and can be used anywhere old-style incandescent bulbs could.
Minuses: They're more expensive and don't give you nearly the savings on your electricity bill or the longevity as the other two. The bulbs also burn hot.