The question here is what format you are looking for
By definition 480i is the best you are going to get out of svideo or rca jacks. so anything over (xxx)x480 is just filler.
Once you start getting into HDTV then you have a great deal more content to play with 540, 720p, 1080i, etc. (maybe we can drool hard enough and get 1080p ! someday soon !)