This forgotten masterpiece was one of my favourite 80s horror experiences. I saw it in the West End, probably on quite a small screen because it got a very limited release, I’d had a few beers with my date for the evening, and we had great, raucous fun with this ridiculous tale of sex-hungry aliens invading earth. Lifeforce is as close as I’ll get to science fiction on this list – a lot of it is about space ships and strange life forms and so on – but the real point of it is to see hot naked actors and actresses seducing witless humans and slurping out their vital juices. At the time of release – 1985 – the scenes of emaciated bodies killed by sex were uncomfortably realistic, but director Tobe Hooper was never one to let tender sensibilities stand in the way of a good yarn. There’s a great cast (Patrick Stewart, Frank Finlay, Peter Firth) working hard to keep a straight face, and some outrageous set pieces including the London-based climax which involves a space ship blasting out of the dome of St Paul’s.