by Waxlimbs on Tue Nov 10, 2015 6:35 pm
Ableton's is pretty good actually, especially if you know exactly what you need to do with it- I also like the native glue compressor for softer compression styles.
In terms of 3rd party stuff, I like Native Instruments' Supercharger, though it's $50 at this point in time (got it for free as part of a promotion). It's super nasty if you want it to be, but can gently squeeze things in a subtle way as well.
Otherwise, I'm not really sure. Like I said, Ableton's has been good for my uses for a long time, and the only other stuff I've used has been rather expensive/owned by a friend. Try shopping around a bit and see if you read any articles about great freeware- there are loads of "Best 10" type lists out there.

Good luck!
PS: A really great freeware plugin bundle that I love is
BlueCat's bundle. No compressor there but some great basic tools to try out.