The fix for the RROD is simple, albeit somewhat time consuming. First, you take it apart(be sure to use a hair dryer on the MS holo-sticker if you don't wanna void) and remove the X-clamps, remove the heatsinks, clean the chips, apply good thermal paste(arctic silver) and then bolt the heatsinks down without the clamps.
If that fails you escalate to the next phase, which while even more time consuming is guaranteed to work and is dead simple. First, take your system apart. Next go out to Gamestop or Walmart and buy a 360(new or used, you choose). Now take that new 360 apart(take care to hair dry the MS holo so you don't mangle it) and set it aside. Grab your busted 360 guts and bolt them into the new 360 shell. Now take the new 360 guts and bolt them into your old shell(this is to make the serials on the outside match).
Now, just take the 360 you bought, which now has your busted guts in it, back and get a full refund. The only caveat is if your old system doesn't have HDMI and the new one does, as the shells won't match up. In that case you have to very carefully remove the serial decals and swap them around. Just use a hair dryer and a knife to pry it off without damaging it.
Sure, this method is devious and probably not entirely legal...but, fuck I want my system fixed now, not a month from now after I mail it in!