10. Christoper Reeve as Superman
He made us believe a man could fly. Somehow breathing absolute conviction into a fundamentally absurd role, Reeve took the fine legacy of Siegel & Schuster via George Reeves and gave it the authenticity it needed to work. He was the first to really make us believe in an on-screen superhero, paving the way for the Spider-Man flicks and Heroes. And did he ever look the part – both nebbish and hunk, we could even go along with the glasses-disguise bit.
9. William Shatner, Leonard Nimoy and DeForest Kelley as the core Star Trek crew
Sometimes lightning just strikes in a casting lineup, and it did here. Wagon Train to the stars wouldn’t have hit the culture nearly as hard if it didn’t have the incredible chemistry between these three to anchor every episode. There’s a reason we have Star Trek conventions and not Lost In Space conventions, and these three actors are that reason. Notably, only Nimoy was in the pilot episode shot for the show.
8. Alyson Hannigan as Willow Rosenberg
Whedon’s Buffy TV series was never as much of an ensemble show as he claimed, but it would have been even more narrowly focused on Buffy without Hannigan in the cast. Her expressive face and unique line readings made her the emotional channel for the audience – whatever she felt, we felt. She gave us the grounding we needed to buy into Buffy and Xander and Giles and the universe that grew up around them. And of course, without the Buffyverse, modern TV would look very different indeed. (It is worth noting that Hannigan is another recast – in the pilot her role was played much more conventionally by Riff Regan.)
7. Viggo Mortensen as Aragorn
Lord of the Rings was a huge success, and is well on the way to becoming this generation’s Star Wars. But without Mortenson, the whole edifice would have come crashing down. More than most fantasy and sci-fi movies, Lord of the Rings relies on audience buy-in. At its centre it needed a person of absolute integrity whose belief can be shared by the audience. Mortensen filled that role. His commitment to the part is legendary – living off the land with his horse during filming, disappearing into the character – and we believe him every second he’s on screen. And without him – just imagine Orlando Bloom’s flat Legolas and John Rhys-Davies’ hamming Gimli without an Aragorn of particular gravitas to balance them. It hardly bears thinking about. (And, yet again, this was a recast – shooting was underway when first-choice Aragorn Stuart Townsend was given the boot and Viggo got the call-up.)
6. Sigourney Weaver as Ellen Ripley
The cast Ridley Scott assembled for Alien was incredible. John Hurt, Ian Holm, Yaphet Kotto – this was the real deal. And yet the movie hung on its unheralded, inexperienced young lead, Sigourney Weaver. Scott’s faith in Weaver was rewarded, as she gave a performance simultaneously tough and vulnerable, all by herself making the female action hero a possibility. Weaver’s Ripley casts a long shadow over film and TV that followed, and her Academy Award nom for the sequel was well-earned recognition of this fact.
…the rest next week. Who are your picks?

