Handheld games are being dominated by Android Phones/Tablets (and some of those new Android media players). I'd recommend getting a high quality Android phone and you'll be satisfied. Internet wherever you go if you have a 3g/4g data plan. Can download emulators+roms not to include the Market Games & Apps. Also used for communication. You'd be way better off buying a phone or just getting an iPod Touch. Then again, you could be a 12 year old kid and have no use for a phone.
As you may not think, I dont have money for a SGS II. Now I got a Moto Droid and it's pretty good, for a 3-year-old phone. It still can't run emulated games. And nobody will give theyr Vita for it :/