He is of course best known for his acting roles. He was quite involved with Hammer Film Studios, where he was well known for playing Count Dracula and other villainous characters. He was acting almost to his death, with a resurgence of popularity in the 2000s with high-profile roles such as Saruman in the Peter Jackson Lord of the Rings trilogy, Sith lord Count Dooku in the Star Wars prequels and Flay in the Ghormengast mini-series.
However for me there are three roles from the 1970s that define Christopher Lee: the Bond villain Scaramanga in The Man with the Golden Gun, Lord Summerisle in The Wicker Man and the subject here, le comte de Rochefort in the Richard Lester films The Three Musketeers and The Four Musketeers. I'd been meaning to get a copy of this model for many years, and with my most recent order from Eureka Miniatures I have finally done so. Lee's role in the film was fantastic, his interplay with both d'Artagnan and the Cardinal was fantastic. He was (I believe) the first actor to play Rochefort with an eye patch, but since Lee's villain was so great, the eyepatch has become almost de riguer for the character ever since.
Unfortunately the sword broke in transit and I've not figured out a replacement yet!
I'm aware of several other miniature versions of Christopher Lee. There were several versions of his Saruman character done for the Games Workshop LotR Strategy Battle Game (I even had a couple of them in the ancient past, but they went to Ebay just before my move to NZ - still kicking myself for that decision). Shortly after his passing, Warlord Games made a WWII version of Flying Officer Christopher Lee as well. I'm sure there are many other characters as well - no doubt several vampire models are inspired by his take on Count Dracula!