Some will drool...
http://www.retrogames.co.uk/
http://interesting-devices.com/index.php?main_page=index&cPath=68
The first thing that came to mind was :P
(http://gifrific.com/wp-content/uploads/2012/04/Homer-yells-nerd.gif)
I do have fond memories of my Amiga though :)
Love firing up MAME every now and again.
I presume AVGN is well known?
http://cinemassacre.com/category/avgn/
(http://i.imgur.com/zHMKWjX.jpg)
doesn't even have a windows key :o
I know these aren't super popular but there is a free Super Nintendo on the Windows 8 App store; you can do touch-screen, keyboard, OR Xbox controls. Just plug in the Xbox controller to the USB port and it instantly works.
I've had a good time with it on my Surface RT but I really need a USB Xbox controller to take full advantage of it.
Adam
(http://s3files.core77.com/blog/images/0icade.jpg)
This yoke makes your ipad act like an arcade game (you've to buy the app to play the games)
There is an iCade Jr. for you iPhone too...
http://www.ionaudio.com/products/details/icadejr
There's a shop on North Main Stret that has old consoles and games for about the same price as retrogames.co.uk but far less selection.
Otherwise find and wipe an old PC, install an emulator and download all the games for free ;)
MAME4droid for Android is working fine as well.
You can also get Sixaxis Controller app and use PS3 controller with you Android device.
a Raspberry Pi (http://ie.farnell.com/raspberry-pi) would probably make a good cheap arcade machine base for anyone with some computer knowledge. bought one but not touched it yet.