Blocky Screen Pixelation & Won't Boot

My (I think '07 or '08) MBP 17" was working just fine.

I was watching a few (very) small .avi videos off the internal drive. All of a sudden, I got some weird pixelation (almost looked like bad VHS video) and then the whole computer hard froze.

I hard restarted, and IMMEDITELY there was weird blocky (horizontal AND vertical) lines on the screen. To repeat, this happened the second the display became bright.

Behind the lines, I get the Apple logo, and the normal loading pinwheel. But after a few seconds of that, I get a dark grey screen, with a splash screen telling me that I need to restart the computer. However, it's 100% unresponsive, so I must hard shut down the computer every time I try to get it going.

Also, I have tried to boot off a OSX install disc with "c" depressed, as well as trying to boot off my brand new Disk Warrior disc.

In both cases, the machine never even recognizes the discs, and just ejects them and proceeds to do the same thing that I already spelled out above.

Really odd, right? Even if the HD were corrupted, it wouldn't prevent me from booting off a DVD. Nor would it explain the odd banding which shows up before the computer demands I restart.

I have already done the RAM trick, to see if one of the sticks went bad, but that has no affect on the frozen machine.

I can deal with the machine being dead, but I would prefer to get the data off the HD, and I don't want to tear the machine apart to extract that if there is a possible remedy first.

Am I doing something wrong when I try and boot off a DVD? I get the disc in as soon as I hit the power button, and hold "c" the entire time. But like I said, it never even tried to boot, and just spits the disc back out after about 20-seconds.

Thanks!