I bought my first compact fluorescent light bulb a few years ago, but I wasn't really turned onto them until my local hardware store began selling them for $1 each. Now, as each old incandescent light bulb in my home burns out, I replace it with a MaxLite Micromax-Spiral. These lamps light quickly, produce a nice white light, and use 1/4 as much electricity as the bulbs they replace.
I even have one outside on my porch. On cold nights, it takes a little longer to reach full brightness than an incandescent, but that's a fair trade for the decreased energy consumption. Now I don't mind leaving the porch light on as much as I used to.
The only problem with these lamps is that they don't dim. I have four rooms with dimmer switches. At first I thought I would have to replace the dimmer switches with special dimmers for fluorescent lamps, but they are way too expensive, costing about $60 per switch. Instead, I discovered this great store (BuyLightFixtures), which sells dimming compact fluorescents. They ship quickly and always get my order right. This dimming CFL is nice and bright at full power, and it dims to a pretty low light level before it starts blinking or shuts off. The lowest dimming level isn't as dark as an incandescent, so I also tried one of these lower power dimming CFLs. Unfortunately, this one isn't bright enough to light a room. I also bought a 3-way, but the old incandescent hasn't burned out yet, so I haven't tried it.