Small video cards?

I think it would be awesome if it was possible to build a console sized computer with out custom made boards. Like a Mini Itx board is good, but Pico would be better (but do to power limitation prob. not possible to do a actual pc, plus they have mini pci-e, so no vid, cards). One time I saw a video on youtube of a system built in a NES case. That is the size I want. Anyway I just want standard boards, PSUs are the real prob. thay are all about the same sizee. I don't know why, but I been thinking about this for a few months.