This is the most addictive and enjoyable little machine ever! I've had my DS for around 2 years now and it's still going strong. It's fell on the floor a couple of times and survived, so it must be well made.
There are literally hundreds of amazing games available for this console and they're not all Brain Training or minigame-based, thankfully!
Buy one, you honestly won't regret it. (But I suggest investing in some screen protectors if you become a DS addict like me :P)
I've been gaming for quite a while. The first portable console I owned was a game boy, The first one I actuary liked was the game boy color, because of it's large game library and link up. I never thought I would like another portable console as much and then I saw the ds (lite). Unlike the psp it looked cool and almost designer like. The long list of nintendo and third-party games for it is outstanding. The thing that hooked me the most however was the fact it's two consoles in one. All the classic gba games you can pick up for fiver (tenner maybe) and there are loads of those as well. The ds games themselves however are a huge improvement over the gba standard, games like zelda ph and animal crossing ww really use the ds's touch screen well while games like worms open warfare 2 show that buttons and the stylus can go hand in hand.
Overall the console has redefined portable gaming for me (and besides I have a psp, I often use it a paperweight for months on end till something decent comes out for it and it's a pretty ugly brute)
There are loooaadss of games out for this, some great ones from the depths of Japan and classics like the Pokemon series. But what trumps the rest is its multiplayer capabilities, purely awesome. Not just for kids and grannies, brain training is actually pretty fun.
Had one of these bad boys for a while now, used to have the old one but upgraded .. glad i did. If i'm honest, i don't play it as much as i used to but it's still a lot of fun when i do. The general idea of ds games are quick bursts of pick up and play. One of the little nifty tricks i've done with with my ds is that using a "R4 Revolution" card and a mini sd card you can play homebrew games and applications. One of the most popular applications used is ScummVM, using this program you can play classic pc games such as Monkey Island and Beneath the steal sky. It is also legal to load roms of your own bought ds games onto the card and play all your games with out the need to change cartridge.
For your infomation the DS can play music ETC ETC as you can get homebrew for it. I've got a Supercard ONE for my DS (4Gig) and currently have 500+ Songs, 2 Movies. I'm currently waiting for the Internet browser with Java which should be out soon for around £20. The DS looks better and previously being a owner of the PSP, the DS is better. Belive me...