Hitch mount definitely works the best. Like said above, Kuat racks are easily the best on the market. But they do come at a price (usually above 500 dollars). You can find the Thule or Yakima racks usually for 20% off MSRP on Amazon or Backcountry.com.
I recently changed racks myself, I chose the Thule 916XTR T2. It came with a lot of nice features for the price, and usually sells for several hundred less than the Kuat racks. Don't know where mfa81 got the Kuat NV for $380, but that was a steal! I paid just under $350 for the Thule 916XTR. It comes with both a locking hitch pin and lock cables for your bikes (I use an extra chain lock for added security). It has tilt features to keep it out of the way when bikes aren't on the rack, as well as tilts down when bikes are on, so you can access the rear cargo area.
Here's a pic of the Thule on the Jeep:
05 Grand Cherokee Limited 5.7L - ORT 4X4
14% Tint ll Weather Tech Mats ll Upgraded Brakes and Rotors ll Painted Calipers ll 5K HID ll Custom Retrofited Projector Headlights ll HIR 9011 Fogs ll LED Interior Lighting ll LED Reverse Lights ll SRT8 Pedals ll Painted Mirrors ll OME HD ll 4xGuard Front/Rear/Belly Skids ll Rola Roof Rack ll Bedlined Rubicon Wheels ll 255/75r17 Tires ll Superchips ll AFE Stage 2 ll Flowmaster Super 44 w/ 3" Tip ll Infinity Door speakers ll Infinity Dash Speakers ll 10" Polk Sub in custom box