I love my PSP for these games:

Final Fantasy Tactics: The War of the Lions
God of War: Chains of Olympus
Final Fantasy VII: Crisis Core

Im going to get:

Patapon
Disgaea
FF1
FF2

Released in the future:

Final Fantasy Agito XIII
Dissidia: Final Fantasy.


Id recommend a PSP, but I dont have a DS to compare it with. Im interested in getting a DS for the FF remakes, but I cant shell out the money atm.