The Kenwood VR-6060 and VR-6070 are both excellent "bang-for-the-buck" receivers. If you check out Home Theater Forum and AVS Forum, most owners of the 6070 highly recommend it as the most affordable THX-certified receiver out there. It's got tons of features and it puts out a lot of power. Minor drawbacks are no on-screen display and low component video switching bandwidth.
Those two models are about to be discontinued for new versions, though.
The "Sovereign" line is obviously their top-of-the-line stuff but I personally don't think they provide anything that justifies the cost over the excellent 6070.