I think Nintendo has the upper hand in the hand-held world. Although so far I've been disappointed by the DS games, I love the GBA games and the disappointment in DS games is because the store here never gets any good DS games. It's as if they purposely try to sell the bad ones.
The PSP does have a lot more features (internet, music, movies, games, etc.) but it's missing the interactivity that the DS has. The DS has the touch screen obviously, but it's also incredibly easy to play with friends. All you have to do is be relatively close and you can play, there is even a download play feature for friends who don't own the game. (Forgive me if the PSP can do this too, I have little experience with them).
On a scale of 1/10 this is how I would rate each Nintendo DS: 9-9.5/10 Sony PSP: 8-8.5/10
And trust me this isn't biased, I love Sony just as much as I love Nintendo.
Don't know where that came from, all game consoles have sucky games, ALONG with the DS. You won't believe how many sucky games there are, its the same for the PS3.
The memory stick for the DS is barely even needed or wanted, wihch is why its cheap, while on the other hand its sold regularly priced for the PSP because it will be bought. The touch-screen is a fun touch, but I'd rather have funner gameplay and a longer-hour fun for a car ride or something like that. There are some great games for the PSP if you look out for them, same with the DS. The DS can addict you a bit longer, though, for some of its games.
PSP also has all the other stuff you can do, too. Such as, browse the internet. And the wireless is way easier to set up. (>.< We have both at home, so it really depends on what you want to do.
It's all you. They both have marked advantages and disadvantages.
ds is the all time best nothing can compeat it has the touch screen and the psp doesn't which makes it the best game console ever made in the world if it wasn't made i might like the psp but, sense it is made it is the all time best in the world