Dude, you gotta throw all those presets away if you're gonna get the hang of this stuff.
'Mixing With Your Mind' has a great summary of dialing in a compressor. It goes something like this:
Start with threshold set to min, ratio to max, release to min, makeup gain wherever, so long as you can hear the output well.
Send a signal into the compressor.
Dial around the attack until the leading edge of each note sounds right; pay attention only to the attack, i.e., don't worry about what happens after the onset of the note.
Now dial in the release until the whole action of the sound is right, i.e., the compressor is engaging and disengaging in a way that's right, musically. It should be unobtrusive if you're doing it right (that's from me, not from MWYM, haha).
Now pull back the ratio until it is at the minimum setting that gives you this nice effect. The idea is to compress as little as possible while getting the benefit.
Finally, pull back the threshold so that the compressor is only working when you want it to be. For most applications, the compressor should not be engaged all the time, it should pass uncompressed sound through much of the time.
Anyway, that's just a rough starting point, but it should get you thinking.
Delete those presets!!
-synthoid