you need both to get the 'full effect' as you put it. DVD for example has a resolution of 720×480 pixels, a high def TV can be 720×1280 pixels or 1080×1920 pixels.
HDTV and a regular DVD player is just low res blown up to the HDTV native res. Reg TV with a HD player, not worth your time, picture will look the same as a regular DVD in most cases.
you need both to get the 'full effect' as you put it. DVD for example has a resolution of 720×480 pixels, a high def TV can be 720×1280 pixels or 1080×1920 pixels.
HDTV and a regular DVD player is just low res blown up to the HDTV native res. Reg TV with a HD player, not worth your time, picture will look the same as a regular DVD in most cases.