Has anyone heard of the GamePark GP32. This is a little known console made by a company in Korea. It is similar in size and appearance to the Gameboy Advance.

It has the ability to play MP3s and DivX videos. But the main reason for getting one of these consoles is the fact that anyone can program for it. This has resulted in a number of games systems being emulated on it, including:

Sega MasterSystem, GameGear and Megadrive(almost)
Nintendo Gameboy, Gameboy Color, NES, SNES and GBA(almost)
and most of the classic consoles have also been emulated

If you want some more info on this fantastic console check out http://www.gp32emu.com/ and http://www.gp32x.com/