I'm a fan of the MXR Dyna Comp too. It has a VERY slow release time, so you don't get that annoying "pop" every time you pluck a note. I like it best with single coil guitars--Strat and especially Tele. I won't play a Tele without one. It tames the highs in a good way with that guitar.
I'd like to try their new compressor too. One cool thing about the DynaComp is that batteries last a long, long time.
lets see--I'm trying to remember the company--Ross maybe? Somebody did a compressor based on the DynaComp, but a few parts were changed and it was also true bypass. Its even more transparent but does its job.