This article will explain the differences between the PlayStation Portable handheld gaming device models. The differences aren’t huge, but of the four models (PSP-1000, PSP-2000, PSP-3000, and PSPgo), each model is slightly better than the other for a specific use case. Which PSP is best for you depends entirely on what you want to do with it.
Ultimate PSP Buying Guide
The first thing to consider when buying a PSP is whether you are going to use it to run homebrew programming, or whether you are going to use it for games and movies. Most buyers probably won’t be running homebrew. It is considerably more work than retail games and requires some programming knowledge.
If you're an avid homebrew programmer, however, you'll want to make sure you get the best model for the job. It's possible to run homebrew on both the PSP-2000 and PSP-3000, but for the most complete homebrew experience, the PSP-1000 is still the model of choice, especially if you can get one with firmware version 1.50 already installed.
You won't find a new PSP-1000 on the shelves, but you might be able to find one used at your local game store, and you can probably still find one on eBay. You'll pay more for a PSP-1000 with firmware 1.50 installed, but if you're going to be playing homebrew anyway, you may want to make downgrading the firmware your first project and buy a PSP-1000 with a later firmware version to save some money.