I might split this out. The compressor I'm talking about is a studio comp similar to Bobby's Avalon. VERY DIFFERENT from comp pedals.
If folks are looking for a more studio compressor sound, but need it in a pedal format, it's worth checking out the Maxon CP-9 Pro+. It's a standard Maxon / Ibanez sixed box, but is a very different beast from the other popular compressor pedals out there.
As has been said above, Keely, Analogman, and other are building some terrific compressor pedals modeled after the old MXR Dyna Comps, the Ross, the Dan Armstrong, etc... Great stuff if that's what you want. I love my Analogman CompRossor, but I'm living in a weird Jerry-meets-Trey tonal space.
Anyway... the Maxon. I tried it for a while, and it really sounds great. Clean, clear compression with a very interesting set of controls. I'm not terribly knowledgable on studio or rack mount compressors, but everything I've read says that this Maxon was supposed to bring those tones into a pedal format. The standard pedals mentioned above definitely bring their own distinct tone to the party. This Maxon is very different. Very clean, neutral compression that seems to me to be much closer to the studio and rack-mount units.
As I said above, I'm flying a bit blind on this one, but if you do need a studio type compressor in a pedal format, this Maxon is definitely worth a look.