Dbz: Attack of the saiyans. This is the best dbz rpg I have EVER seen, its much better than the gba rpgs, where you just kill snakes. This game takes it back to dragonball, and even has some never before seen footage. Even if you don't like rpgs, this game is easy enough to please anyone. Although it's pretty easy, only requires some grinding, and even the grinding is fast. My game time was 43 hours on this game, very excellent.
Beyblade: metal masters. Recent game I found out about. I must say the gameplay is awesome and is a very nice action game. It's the latest one, so I'm definitely eager to play its previous titles.
DBZ: Super sonic warriors 2. A nice easy action game, once you get the hang of it with blocking and such. You don't have to like DBZ to enjoy this, like attack of the saiyans. In my opinion one of the best action games for the ds. The blocking function pretty much ruins the whole difficulty for this game. You just press b when someone rushes and tries to attack and then you attack back. So easy. If you have a friend, you should try playing this game with them. The multiplayer is nice and I play it frequently.
Call Of Duty: MW3 - Defiance. Best fps shooter game out there, the graphics aren't that great, but hey, it IS the ds, afterall. The multiplayer lets you use wifi, this game isn't for everyone, infact its filled with 10 year old kids who thought this game was cool and begged their parents to buy it. It's a good experience once you get the hang of it.
Now I'll just stop making reviews and give you a list of some games, as I feel like being a fatass.
Megaman zero collection
Mario Kart
metroid prime hunters
mega man zx
mega man zx advent
mario hoops 3 on 3
jump ultimate stars
tony hawks proving ground
ed edd n eddy scam of the century
contra 4
ultimate mortal kombat
final fantasy XII revenantwings
super dodgeball brawlers
final fnatasy IV (Only ff game I've spent more than 15 hours on, still not done completing it though, as it is hard as balls.)
N+
Commando steel disaster
chrono trigger
pokemon platinum, black, white, gold, silver, any pokemon game out there.
Kirby super star ultra
Kingdom hearts 358/2 days
Kingdom hearts re:coded
cop the recruit
space invaders extreme 2
fifa 10
fifa 11
ace attorney pheonix wright
ace attorney investigateions miles edgeworth(barely started it but I can tell its decent)
All yugioh 5ds games, of course.
Chicken Blaster
Demenitium, Dementium II (BEST HORROR FPS GAME OF ALL TIME, JUST MIGHT BE MY FAVORITE GAME ON THE DS.)
100 classic books (Some good old classics, eases the mind of killing zombies and stomping on goombas)
xg blast
james bond 007
sonic colors
duke nukem
plants vs zombies
ben10 triple pack
kung zhu
x men destiny
advance wars days of ruin
aliens infestation
bomberman
All castlevania games
Fifa street 2
GTA chinatown wars
Naruto vs sasuke
Konami Arcade collection
mario party
metal slug 7
need for spped underground 2
okamiden
phantasy star zero
kirby squeak squad
ninja gaiden
summon night twin age
yoshis island
Those most of the games I've played and enjoyed on my ds. Well I put all my effort into that. Great system, great games. Now off to the 3ds.