Ice on Mars
Star Trek Voyager s1e03, "Time and Again"
Picture a pitch room in Hollywood. Braga and the usual suspects litter the room. Someone brings up the idea of doing an episode of Voyager about a cut-off alternate future, where effect PRECEDES cause. Someone else says, 'Maybe we should check and make sure we haven't done that already?' And someone else—probably Braga?—says, 'No, we've only had two episodes, NO WAY have we done that already.' Then everybody laughs and PROBABLY there's cocaine involved? Maybe they torture a hobo to death? Whatever.
This is the episode in which Kes's amazing psychic powers to—in the "real" space-time continuum—SENSE NOTHING first show up, and … that's obviously an important continuity point.
You like annoying elf children? Check! You like fashion mistakes that would make Lady Gaga blush? Check! You want craggy white guys arguing? BABY, VOYAGER WILL NOT LET YOU DOWN.