The PSPgo is Sony's latest addition to the PlayStation Portable family. It was released in October 2009. The PSPgo is the first major form-factor change for the PlayStation Portable since it launched in 2005. The PSP-1000 and PSP-2000 are no longer in production, so if you're looking to pickup a new PSP from retailers, you pretty much have these two options. Hopefully a look over some detailed comparison pictures and features will answer some of your questions on which PSP system is right for you. There's also details on all Firmware 6.20 differences on each system. Both systems have 6.20 installed, but did you know all the menu differences?
See 30 comparison pictures and notes of the PSPgo vs. PSP-3000 here.