The CFL's (compact fluorescent lamp) annual cost is $1.69 compared to an incandescent light bulb (old style - ones used for years and years) cost of $7.23, and the light-emitting diode is $1.45 for the same amount of light according to the Denver Post, US Department of Energy, Wall Street Journal and D&R International.
A couple of years ago, we replaced most of our easy-to-reach and frequently used light bulbs. So we wouldn't go too crazy over the rest of the light-bulb thing, here is what we do. Since the light-emitting diode was $30-40 per bulb, we pass on that style - not cost-effective enough.
As for the more efficient and cooler CFL when an old-style bulbs burns out, we replace it with CFLs whenever possible. Not all our sockets can take a full-sized CFL, so we bought a few shorties. And a few of our sockets cannot use CFLs (our outdoor lights on remote sensors don't work right with CFLs, so we replace them with the old-style. And when we replace those old and hail-storm damaged remote-sensor lights, we will search out those that are CFL friendly.
When one of our long-tube florescent lights or a CFLs burn out, we take them to Home Depot or Lowe's for recycling.
Don't know how many old-style bulbs we have left to replace, but the electricity portion of our utility bill is under 400 Kwhs. You could say either we are energy efficient or live in the dark.