Which brain Nintendo DS game is better?

Brain Age is the other official Nintendo game on your list. The others are 'third-party', and are potentially lower-quality games. Start with Brain Age, then see if you can rent/borrow any of the others to see if you like them first. If you're on a budget, you may want to go for the lowest price game. If you go to a used game store, they should let you try one or two of them before you buy (uming they have them used - you can't try new).