Technically any "SDTV" with Component inputs is officially classified as an EDTV (Enhanced Definition Television), at least here in the States. SDTVs can't do 480p, but EDTVs can.
And yeah, a late-model EDTV would be a great investment for any Dreamcast/PS2/GCN/Xbox/Wii gaming. I find that it's not really necessary for stuff prior to the Dreamcast, though--I can finagle my HDTV settings enough to make older games look as good as ever (and I always use an S-Video cable whenever applicable instead of Composite Cables for pre-DC consoles).
--
Thank you, Eddie Guerrero.
http://img.imgcake.com/Icon/Punkjpguh.jpg