For those of you into retro gaming and want a machine that can be both portable and a system, the Retro-duo RDP is worth looking at. A friend of mine picked up two of these recently:
http://compare.ebay.com/like/360532047343?var=lv<yp=AllFixedPriceItemTypes&var=sbarBasically the system can play snes and nes games out of the box. Genesis games can be played with optional adapter and gameboy games with a super gameboy. We tested both of our systems and found 99% of the games we tried worked without issues. Some of the snes games that give other systems fits worked fine like Mario rpg, Yoshi's island, megaman x 1,2,3, earthbound, and mario kart. The screen is very good and the system is comfortable to hold.
Here's the catch. The quality of the system seems to vary from batch to batch. After a ton of research it seems that almost everyone has atleast one minor problem. A handful have huge issues. The controls on our systems were very good, with mine being just a tad more stiff. Sound however was abit louder on my system than on his. Plugging in headphones not only solves this issue, but has excellent bass output and very clear stereo sound. All games tested (around 100 various nes, snes, and gameboy games, we dont have the genesis adapter) all of them worked on my machine. Two games did not work on his, doom and yoshi's island for snes. it could have simply been a variation in the cart slot that caused the problem. The battery lasts twice as long as other comparable systems at roughly 6.5 hours (they claim

. It comes with external hookups for real snes controllers and outputs to the tv allowing multiplayer games and to be used like a system.
For me the lowdown is it worked very well and i have no complaints. Many have bought one and had issues only to exchange it and get one back that was near perfect. Despite two minor issues or machines performed excellent.
Now all they need to do is make a portable turbografx with sdcard support that loads cd games and i will be all set
