I have a desktop PC currently sitting next to my TV in a small-ish case but I'd love for it to fit on the shelf in my TV cabinet. I've had a little look around but haven't been able to find any PC cases supporting a full ATX motherboard laying flat. Ideally I'd like to house a full size GPU as well (for gaming) and use a PCI extension cable so it can lay flat.
It looks like I might have to make something myself, but thought I'd try here in case someone else has gone down the same path before and found a decent case.
I suppose the other option is to buy a smaller motherboard and look into something like the Silverstone Milo or Lian Li HTPC cases.