Get her the Daxter PSP game. I’m very familiar with Playstation game titles because I’m strictly a Playstation guy and I’m familiar with Sony’s games. I’ve played the Jak and Daxter adventure game series for the PS2 and I loved them.
My 18 year old little sister loved playing the Jak and Daxter series for the PS2 and it’s a very fun game title for anyone to play for both hardcore gamers and casual gamers alike. You can’t go wrong with the Daxter game for the PSP. I think that it just costs $19.99 also.

psp huh?
well for a 16 yr. old girl? im not really sure but id recommend….
i have a friend who’s a girl who has a psp and she likes:
need for speed prostreet
need for speed carbon
both racing games
and hmmm…. girls always liked the sims series so i’d recommend the sims 2 for the psp
those are really the only games i recommend cuz i dont like recommending action adventure games on portable gaming systems cuz usually once you finish one you’ll probably not play it again so racing games sports games multiplayer games and games that don’t really have a storyline and kind of never end are probably the best choice….
hope this helped you out!:D
don’t forget to pick a best answer!

U should get her Lumines. Its similar to tetris as in its a puzzle game that is timed, but it has a musical element to it so it isnt as old school as tetris. Its very easy to play and can get very addicting. Its also been out for a while so it should be cheap