The one's with candlelabra bases are not very common but medium (regular sized) based ones are easier to find. Most of the dimmable one's I'm comming across now are CFL reflectors. My WalMart has R-30 CFL reflectors by Lights of America and GE.
I have the Lights of America but it's somewhat erratic when I tried it with a dimmer I had laying around (Rotary knob dimmer made by Lutron in 1993) so I don't actually use it with a dimmer currently. You have to turn the dimmer up to about the 30% mark to start the bulb and it's best to warm it up on 100% power otherwise it will look very pink. When you dim the light, it stays at about full brightness until you turn the dimmer down to about 80% where it will quickly drop to about that light output but it will continue to dim smoothly until you reach 25% where it will then drop suddenly to a very dim level and flicker a lot until you get to where the dimmer shuts off. I haven't tried or reviewed the GE one yet.
My other one is a Philips Earthlight Dimmable 20 watt (75 watt incandescent equivelent. I found them at BigLots for about 3.00$ each. With the same Lutron dimmer, they will start at about the 15% mark on the dimmer and ramp up and down very smoothly as if it was an incandescent. It takes about 15-20 seconds to reach full brightness when you first turn it on (crank the dimmer up all the way) but the color temperature once warmed up is very similar to an incandescent lamp. In a table lamp with the bulb hidden by the shade, it's hard to tell the difference. The only thing with dimming is that it gets pinker when you get down below 60% and at the lowest setting on my dimmer, it's still as bright as a 15 watt incandescent bulb while a 75 watt incandescant bulb I had wired in parallel for comparison only had a tiny, orange glow from the filiment.
My Home Depot used to have the Philips Dimmable CFL but they only now have the R-40 reflector version which is the same but has a reflector around the tubes. You could probably break that part off and use it as a "regular" bulb in a wall sconce or table lamp. The Philips bulbs are not the spirals that are popular now but rather three U shaped tubes next to each other comming out of a plastic base so they are longer than most spiral CFLs.
http://www.buylighting.com/20-Watt-P...-p/sls20-d.htm
I've also seen the Greenlite 23watt dimmable CFL on Smarthome.com but I haven't tried it yet. I do have some of their non-dimmable versions and they seem pretty close to the Philips CFLs in terms of color temperature and the way they start and warm up. Smarthome says they also work good with X-10 and other remote controllers for home automation. Another one I've heard of is a 26 watt model by GE but I haven't tried that one as well.
Greenlite Dimmable
EFI's selection of dimmable CFLs