@nocontexttrek Wow, that's a hard one, especially since Iggy Pop has been mentioned multiple times already. Regarding #TOS, I'm torn between Joan Collins and Ted Cassidy (Addams Family). For #TNG, the wonderful Bebe Neuwirth has been named here too, so I'll propose Famke Janssen. And Lori Petty in #Voyager.
But my favourite has to be from a movie - not the best of the films, mind you - but what a fabulously bizarre, poetic and funny performance by the great #Iman in #StarTrek VI!