Everything, if I am going to put them ON the DVDs.
I love listening to the soundtrack by itself - It wouldn't have to match up to the video perfectly, and there could be a recommendation on the menu to turn off one's TV for that particular soundtrack option.
And Bizzle, uncompressed WAVs would be nice, if at all possible. (I know how big the file sizes can get.) My original AC3 was made out of necessity, not personal preference (plus it was a case of "can I do this?".
)