Kingdom Hearts: Birth By Sleep

I was honestly surprised by it as I haven't really enjoyed any of the other handheld KH games. Chain of Memories wasn't that bad considering it was on the GBA. But 365/2 and Re: Coded always felt really clunky.

Although admittedly my PSP was busted so I emulated it on the PC, but still - I loved it, especially Aqua's storyline.