Let me get on my soapbox and elaborate on my "bad movies should be remade" comments -- IMHO, "Showgirls" and "Plan 9 from Outer Space" are in the so-bad-they're-good category, like "Valley of the Dolls" and "Whatever Happened to Baby Jane". You could remake them into good movies, but that would take the charm out of them, kind of like the campy "Lost in Space" being remade as a straight sci-fi drama.
Movies like "Bonfire of the Vanities" are just plain bad, but they could have been great, since the source material was so good. "Striptease" was a hilarious book, but a bad movie -- why not remake that one? "Godfather Part III" should be redone in keeping more in line with the first two movies -- get back Robert Duvall, lose Sofia Coppola, stop allowing Al Pacino to yell, etc.