I'm definitely going with the first choice: whenever you have a successful TV series, doing a movie on it only enhances the "magic" the show endeared itself with to us, plus there's always something exciting about seeing your favorite characters on the big screen (still wish something came into fruition regarding a Courage the Cowardly Dog movie); whereas when you try to do a TV series based on a movie, the series always falls flat of measuring up to the original movie (M*A*S*H being the exception, of course).