* With high energy costs driving up electricity bills and an ever-widening array of lighting choices available at the local hardware store, it can be hard to pick the best and cheapest lighting option.

The first light bulbs are incandescent. Basically, these bulbs follow Edison's original design: an electrical current runs through a filament in a glass bulb. The filament then heats up, emitting light, as well as a lot of heat.

In terms of base price, incandescent bulbs seem like the cheapest option: a four-pack costs somewhere between$2 and $3. But the cost goes up once you screw them into a lamp: incandescent use between 20 and 100 watts per hour, which translates into 2-12 kilowatts per month. Also, they don't last too long: most bulbs work for between 750 and 1,000 hours, or 6-8 months, which means that they need to be replaced fairly often.

They are also the most convenient lighting option. Incandescent bulbs can be used with dimmer switches and are available in a wide variety of shapes and sizes.

The current light bulb leaders are compact fluorescent lamps or CFLs. Part of the reason for this is cost: although their price has dropped in recent years, CFLs still run $2 and up per bulb, about four times as much as incandescent bulbs. On the other hand, CFLs also last a lot longer: most will run for between 6,000 and 10,000 hours, or 4-7 years of normal use. In fact, given that they will run for 6-10 times longer than incandescent, their basic price is up to 50% less than incandescent bulbs. And CFLs also use a lot less electricity: a 26-watt compact fluorescent puts out as much light as a 100-watt incandescent, but only uses about a quarter of the electricity.

CFLs also have their downside: depending upon the brand, they may flicker a bit, and they cannot be used with a traditional dimmer switch. They won't work with some lamps and attempts to expand the array of CFL shapes on the market have been mixed.

The brightest option is probably light-emitting diode LED. A nine-watt LED bulb puts out as much light as a 40-watt incandescent, but will last for 25,000 hours, or up to 23 years. They also don't present the same mercury hazard as CFLs, which makes them easier to throw away. Then again, with 23 years of life, chances are that you'll change your lighting fixtures more often than you'll change your bulbs.

Unfortunately, LEDs are prohibitively expensive. They run about $40 apiece; most LED bulb makers are small companies with limited production runs. On the bright side, General Electric and Sylvania have both announced plans to release LED bulbs later this year. While the new lights will probably be exorbitant in the beginning, competition should bring prices down.

In the meantime, though, the basic choice is still between incandescent and CFLs. Over the course of seven years -- the lifetime of a CFL -- the bulb will use about $25 worth of electricity; with the $2 initial price thrown in, this translates into a total cost of about $27. By comparison, an incandescent bulb will use about $96 worth of electricity, and will need to be replaced about eight times, leading to an overall cost of about $100 dollars. Given the costs and limitations, your best -- and brightest -- choice is a CFL.