11. Robin Curtis - Lieutenant SaavikFilms: Star Trek III: The Search for Spock (1984) & Star Trek IV: The Voyage Home (1986) Replacing: Kirstie Alley It might seem ridiculous to say so now, but Star Trek II: The Wrath of Khan was originally intended to be the last Star Trek film. The critical and commercial failure of Star Trek: The Motion Picture led to the second film being made on a much lower budget, and the fact that Spock was being killed off in its climactic moments put a feeling of finality upon proceedings. But once TWOK became a commercial hit, producer Harve Bennett began planning a further sequel, which subsequently became a loose trilogy with Star Trek IV: The Voyage Home. Most of the core cast of TWOK returned for Star Trek III: The Search for Spock, with Leonard Nimoy stepping into the director's chair as well as reprising the title character. But Kirstie Alley, who had played his half-Vulcan counterpart Saavik, did not return. Saavik was Alley's first big screen role, and due to a legal oversight her contract did not contain any stipulations regarding a sequel. Worrying about being typecast, Alley demanded more money but Bennett refused and replaced her with Robin Curtis for the next two films. Alley's performance as Saavik is one of the more under-appreciated aspects of TWOK. It's a thankless role in some respects, having to play the by-the-book rookie against the experienced crew of the Enterprise, but Alley brought an earnest commitment to the role which made it more than the "tits and ass" performance that the producers wanted. Curtis, by contrast, isn't particularly charismatic and seems uneasy amongst all the prostethics and silly costumes. While Alley worked hard to make her character rounded, Curtis allows Saavik to become at best an awkward distraction.