The NOVA shopping center is located close by the Taipei main railway station. It's a large collection of many stores selling all sorts of computer stuff from printer cartridge refill kits to full desktop systems.
NOVA is my second stop after Bade rd. The shops there carry all sorts of electronic goodies. MP3 players, cell phones, computer components and storage media. Definately worth the trip, but I wouldn't buy anything before checking out a few different places and prices.