I would never buy any DLs at regular price, the recommended would be Verbatim, but just keep an eye out for when they go on sale, then snap them up. You are dealing with a bigger file, 5+, 6, 7 or 8 GBs rather than the 4+ GBs to fit on a SL. Most of the time I will take Movie Only plus 5.1 English, but not proceed if the setting drops below 70%. For episodic Dvds I will sometimes cheat, then I follow this guide supplied by jellybean. Less than 65% - Maximum Smooth, 65 - 80% - Smooth, 80 - 90% - Default Sharp & 90 - 99.9% - Maximum Sharp. I am not saying this is the best deal around, but just found it after replying to your post.
http://club.cdfreaks.com/f58/50-pack-verbatim-dvd-r-dl-media-49-81-less-sams-club-251486/