The absolute best to me is Mario and Luigi 3: Bowser's Inside Story

Shocking how funny it is. And considering the lineage, that's such an accomplishment.

The World Ends With You

Golden Sun! =D

Dragon quest IX -> the game is just flawless, the stories were superb, the art direction & music pearless... I can not really express how much I LOVE this game!

second place is tied to: Valkyrie profile: covenant of plume, SMT strange journey, P3P (even though I hate the ending) mario and luigi: bowser's inside story, TWEWY, Radiant story... Too much RPG love!!

P3P was a fantastic remake. The visual novel style overhaul actually worked incredibly well for a handheld. I also enjoyed how the female felt like an entirely different character as opposed to a re-skin.

I'd give TWEWY a close second due to being one of the few DS games that actually utilized dual screen gameplay extremely well and came from Square Enix during a period where they rarely released quality titles.

Also where's Bowsers Inside Story?

The remake of Final Fantasy IV. Always been a favourite of mine, and the remake was very well handled, to say the least.

No Crisis Core?

K.

BBS

Of the ones listed... Radiant Historia

What a game!

Most of the times you want to delay the battle just to listen to this

The World Ends With You, End Thread.