There are quite a few portable gaming systems that are out there.  I know with me I prefer the handheld systems over the consoles.  The portability is the key I can lay in bed and play or keep it in my desk drawer at the office.  I have always loved video games, but as I get older there just is not enough time in the day anymore and thats way handheld systems are so perfect, just relaxing in my chair playing Metriod Prime Hunters(awesome game). I will go over some of the systems are are out right now and hopefully this will help you choose the right platform.

Gameboy/Gameboy Color:  These two systems are very old and out of date, in my opinon they are best used as a paper weight, there is just no point in buying these handhelds anymore because you can barley see the screen the colors are so bad and all the games that they play are playable in the newer systems.  Ebay is really the only place I have seen these systems being sold.  If  you want cheap go with the advance or Micro.      My Rating: 2.5

Gameboy Advance and Micro: I remember when the Advance came out with the new gameboy advance games.  The Advance is the way to go if you want something inexpensive or for your kids since they will probably end up breaking it anyways.  The Advance is nice because it is back compatible meaning it will play old Gameboy and Gameboy Color games.   The Advance does have a color screen, but it is not back lit so night play is out unless you have a worm light or like accessory.  This system also have a very comfortable set up with the addition of 2 new buttons on the top of the console.  You will still need to use batteries( 2 double A's) which gets aggravating, but the Advance is a good way to go for a inexpensive or if you buying your first console because you can always upgrade later and your games will still be good.  Now for the Micro, all I have to say about the Micro is, it is too small you would be a fool to buy this, why so you can lose it(yea it is that small).  The main difference with the Micro is that it is tiny, you can change to face plates, its rechargable, and you can play it in the dark the screen lights up.  I do not recommend this console, the SP is just as portable, and its not that much more expensive.     My Rating: 5.5

Gameboy Advance SP:  The SP is a great system, it plays the new games and is also back compatible with all the old ones too.  The SP has the flip top to really make it a great portable system. No more batteries, the Sp is fully rechargable with a built in lithium-ion battery that charges very fast and last pretty long. With the SP there is no longer any need for lighting attachments the screen is back light so it is playable in total darkness.  This is a big step up from the Advance when the SP in folded up its about the size of a wallet which easily fits in your pocket.The graphics on the new gameboy advance games are very impressive for such a small system you will not be disappointed.  A brand new SP will run you 79.99 and at the price with the system you are getting I highly recommned this system.  My Rating: 7.5

Nintendo DS:  The Nintendo DS is really the first of its kind.  It has a flip top like the SP does but it is also double the size.The DS is very different it uses two screens one being a touch screen, which makes gameplay very cool also the addition on 2 more new buttons from the SP.  Like the Sp the DS is back compatible and has its own line of games and the 3-D  graphics are very impressive.  The lower touch screen really puts this system over the top with now having the ability to play 3-D games.  It does take a little bit getting used to, but its not to difficult.  The screens on the DS are much brighter than the SP and can be played in total darkness.The DS is also fitted with a rechargable battery that really lasts.  The DS also has a built in WiFi for mulitplayer, which means no cables between consoles and the other player doesnt even need a copy on the game in most cases.  The DS can jack into any wireless internet connection and you can play people around the world and best of all its free.  The only real con with the DS, it is a little on the bulky side and the touch screen takes some getting used to but being about 50 dollars more than the SP, this system is very nice a well worth the price.    My Rating: 8.0

I hope this guide has helped in you making your dession in your gaming platform and I will be adding more systems on when I have to time.