Have you tried Onlive
? If so what was the experience like in your area? It is free to sign-up for and to play 30 minutes of almost all the games they currently offer.
In my area, or at least from my house, my experience has been excellent. Almost no lag or delay. I'm in Southern California, Riverside county. Lucky enough to have an Onlive datacenter only a few miles from here.
Oh, and I have a 10mbps Cable connection.