first of all this is just my opinion, but i own both the psp and ds lite, and i think that the ds is probably the biggest waste of money. If it weren't for pokemon and mario kart, which were two great games with enjoyable multiplayer, i would say that the ds is completely useless. ive tried other "great" games such as advanced wars, elite beat agents, zelda (i was severly dissapointed), brain age, and pheonix ace attorney, and think that they are all mediocre games with the excuse of being "innovative". DS is just like the wii, which basically has no real games.

On the other hand, i've found my psp to be a lot more usable and have better overall quality games. no ds game can come close to games like wipeout pure, monster hunter, twisted metal, syphon filter, battlefront, tekken, metal gear solid, socom, and crisis core, just to name a few.

in the end, ds is nothing compared to gb/gbc/gba/psp, all have which have worthwhile, quality games. even for some of the games that are console-like, id rather play those than these so-called innovative games. these console like games are especially useful for long trips on airplane/subway/car.