Two weeks ago, my best friend and I drove to the local Air Force Base and purchased a premium Xbox360.  As you can gather from the previous post, it was a very good moment for us.
On the day after he bought it, he recieved the "red ring of light" on his 360, and the system notified him that it could not read the current disc.  This happened with all 3 games he's played: The Elder Scrolls IV, Perfect Dark Zero, and Gears of War.  The Elder Scrolls and PDZ were both brand new, and Gears was borrowed from a friend and in near mint condition.  (Gears of War works fine on said friend's 360.)
So, we took the 360 back to the BX that we purchased it from and exchanged it for a new one.

No more than a day later, the new 360 breaks also.  We can't play a single game for more than ten minutes without it giving us a disc-read error.

I've already checked around both on the Xbox360 forums and on the Xbox website, and so far I haven't found much useful advice besides "contact Microsoft and send in the console for repair", though I'm not sure how much that would cost.

If anyone has any suggestions for me, please let me know.  Honestly, I'm pretty annoyed right now.  There's no real excuse for the sheer volume of broken 360s that I've been hearing about both from friends and 360 owners around the net.
"Give us $400 and maybe your console will work!"  Not the best philosophy in my eyes.