If you have a Dreamcast you need to have a VMU. Especialy if you have it connected to the internet. Like a memory card a VMU saves game information like options and seasons but you can also download animations and VMU games on the internet.However there are also bad things about the VMU. Sometimes one game takes up almost all 200 blocks of memory. There are only a few VMU games to download and the only one I really liked was Tetris. A VMU costs ... dollars when a normal memory card costs about [price].Still I think all Dreamcast owners should have at least one VMU and maybe some normal memory cards or an 800 block memory card. Or more VMUs if you don't care about any of the problems.