I tend to use compressors mostly for vocals (and percussive elements sometimes) as they have a lot of dynamics, and so the need to even them out.
Other that that, a good EQ tweaking before the recording, and a balanced mixing overall, pretty much eliminates the need for compressors.
That being said, I tend to use Ferric TDS a lot as a master effect. Pretty nice virtual effect. It says it's a Exciter/Enhancer, pretty much works as a compressor, I guess. I'm not a Pro, obviously. It lets the highs stay sharp and the lows stay deep without eating away the other freqs, so I love it.
I find Limiters actually very helpful, whenever the final mix is not as loud as I wish it would be. And btw, "final mix"= after all peaking is eliminated.