PlayStation Portable/Homebrew

I want to get a PSP, which one do I get?

Years ago, the answer to that would've been "A big old PSP-1000 (Fat) and a huge-ass memory stick". However, with the cracking of the PS3's Master Key (and thus the ability to sign things so that the PSP's stock firmware (AKA official firmware or OFW) can run it), and the release of Infinity hybrid firmware, things have changed. As such, if you have no PSP right now, your best bets are the PSP-3000 (if you need to play UMD games) or the Go (if you don't). Mind that the Go has 16GB built-in, with only an expensive proprietary memory card available unless you do a hardware mod for MicroSD cards.