I know that this topic hasn't been added to in a while, but it's not the sort of topic that goes dead really so I thought I'd add to it with my current set-up:
I've taken one big picture and a couple of close-ups.
Main Picture:

Close-up right:

Back to front: Tectoy SMS3, PS2, Amiga CD32
Close-up left:

Top to bottom: RetroCon (NES clone system), Mega Drive (on top of sky box), Master System (on top of DVD/VCR), PC Engine Duo
Close-up main systems:

Not pictured in a little pile further to the right Amstrad GX4000, NEC Super Grafx, PS1 (I don't have room for everything to be set up at once!)
These are just the systems I have hooked up right now, and I couldn't possibly get all of my video game stuff together for one photo - staying in a smallish flat, it's scattered all over the place between four rooms and in various cupboards, on shelves, in drawers etc. Still, hope you enjoy!