Thule Tour Pannier Rack
Patented rack attachment system works on virtually any bicycle from full suspension mountain bikes to commuters and everything in between.
This is the rack that fits the bike that no other rack fits. Watch their demo video to see what I mean: http://www.thule.com/en-us/us/products/sport-and-travel-bags/bike-bags-and-racks/racks/thule-pack-n-pedal-tour-rack-_-pp_100016 If you have full suspension or some other anti-rack quality to your bike, double check with this one. It'll probably work--front or back. Unless you're just mounting a trunk rack, you'll probably also want the pannier frames: http://www.pricepoint.com/Brand/Thule/Thule-Pannier-Rack-Side-Frames.axd I gave it four stars only because it's a bit flexible and doesn't handle uneven loads very well. Other than that, it is superlative.