I was just playing Resident Evil 5 and without warning my 360 shut itself off. I turned it back on and about 5 minutes later it did it again while I was at the dashboard. No red ring or anything, just shuts down.

Has this happened to anyone else? How can I fix it?

Is it in a place where it can heat up fast?

Sounds like your power supply is dying. That is all I can think of, I am used to seeing 3 beautiful red lights myself.

hard drive is probly fried

I saw this on Terminator: Sarah Connor Chronicles.

Never had that problem. My problem is that my Xbox's disc tray keeps openng randomly, but it never actually opens. It just puts it in an "Opening . . ." status. Pain in the ass, really. Also, I've been electrocuted by it before.

I have the opposite problem, mine seems to randomly switch itself on.  Thankfully, no electrocutions yet.

Well I tried it again and it was on for about 20 minutes before I turned it off myself. Hopefully it was some freak power problem (although it did happen twice). But I figure I should let it rest for a little while.

In Transformers, the cube touched an Xbox and it turned into a Transformer. 

your 360 is possessed by PAZUZU!

mine used to when it would over heat