I don't know how interesting this is but FabFilter's Pro-C 2 is my very favorite plugin period. On the downside it's not that simple, it's pretty feature laden. Also, if you're looking for "character" or "color," it's probably not for you (but for like $25 you can pickup Klanghelm's MJUC have have all the color you ever need) Pro C is clean city. But if you're wanting to play around with mid/side processing, side-chain filtering, etc, in mastering mode, it's pretty deep, and intuitive after a little study
