I have both and I play a wide variety of games on my handhelds as I travel a LOT for work. The DS is the console I find myself grabbing more often than my PSP as I just find the games on the DS to be more fun to play. Top games on my DS include,
Advance Wars DS/Days of Ruin
Dragon Quest V
Dragon Quest Monsters Joker
Zelda
The Phoenix Wright Series
FF Tactics
Castlevania Series
Geometry Wars
Tetris
Fire Emblem
There are a ton of different games I love on the DS, but games I HATE to play on the DS are racing games. I definitely prefer my PSP for those.
Anywho that's my opinion
Oh yeah, and I do brain age almost every day and love the sudoku puzzles.
Advance Wars DS/Days of Ruin
Dragon Quest V
Dragon Quest Monsters Joker
Zelda
The Phoenix Wright Series
FF Tactics
Castlevania Series
Geometry Wars
Tetris
Fire Emblem
There are a ton of different games I love on the DS, but games I HATE to play on the DS are racing games. I definitely prefer my PSP for those.
Anywho that's my opinion
Oh yeah, and I do brain age almost every day and love the sudoku puzzles.