My original upright cabinet is very popular with all my kids and visitors (it has MAME, various emulators, Jukebox, a dance mat, Guitar Hero, and Singstar), and I've just added a trackball, and an EMS TopGun light gun (some spinners still to come).
However, since its so popular and is also in our living area next to the entertainment unit, Fridays and weekends can get pretty crowded, so I've been thinking of a way to break them up a bit.
With money time and space all very limited, I've 'innovated' with this:
Step 1: Buy a cheap clothes cabinet from ebay for
0.99c that smelt like horses and looked like it was painted by throwing brushes of wet white paint at it.

Step 2: Sand it back with an orbital sander, spray it with primer/undercoat, then paint it with water based
MATT BLACK (Matt is my new love). I covered the whole thing easily with a sample pot from Bunnings (AU$8.50) and MATT BLACK is
so much more forgiving than the gloss black that I've painted my upright and one of my bartops with... where gloss black highlights every imperfection, matt black looks classy and hides almost everything (which is great for such a cruddy old cabinet).
Step 3: Obtain generously donated (free) 68cm TV, a late 70's Technics amplifier from a friend, and some big floor standing speakers from ebay, mix it all together and:

I built the shelves out of a single sheet of 12mm MDF ($12) which is just sealed & undercoated, and has semi-circles cut out of the back to route the cables through. They sit on shelf plugs (like you find in a pantry) which are adjustable thanks to all the holes I drilled for them. I used some scrap 18mm MDF and routed a roman edge for the panel that sits across it all (that the TV sits on top of). This gives the DVD player ($30 from Aldi) a great alcove underneath.
I've got all the audio routed through the amplifer into these giant floor standing speakers and it sounds AWESOME with huge base and really clear sound. This makes it ideal for the dancing games, Singstar, and especially Guitar Hero.
It doens't end there however... I've got a dual USB to Playstation2 converter ($5) and the kids can play almost all of their favourite MAME games with the controllers they're so familiar with (leftover from the PS2 I recently sold), and the analog sticks are actually half decent for trackball/spinner style games).
Not shown in the picture is the light gun which I've since added too. The idea of this cabinet is that the screen is the right height for standing in front of for guitar hero/shooting games etc.
I have a wireless keyboard and mouse too to control the PC (a laptop sitting in the cabinet using S-video out to the TV).
I've also put in a bluetooth receiver and I've successfully hooked up the Wiimotes to the point where I can control older MAME games NES style, but I'm also working on the motion/tilting/pointing features to use them as Wii Zapper light guns in MAME and for using the 'tilt' as a trackball in games like marble madness.

This is just a novelty at the moment but if it works out I'll move the Wii into this cabinet and leave the xbox in the back room.
So this my friends, is how you get one very entertaining setup that looks half decent on a very very tight budget.

It won't outshine my upright or the recent bartops, but it sure comes close in function for a
fraction of the price!
I did toy with putting the TV in a enclosure, adding some motorised mirror-reflected lasers through a fog machine with a bubble blower (no, seriously) but that kind of defeats the 'quick project, low budget' concept
