Ben Kinsley as Gandhi
A truly unforgettable performance by Ben Kingsley. Twenty minutes into the movie and you are telling yourself that this is Gandhi on the screen, not an actor. One of the great performances in cinema history.
Zulu is a massive movie with an ensemble cast. Two of the lead roles are played brilliantly by Michael Caine and Stanley Baker. Both men had great success, but their roles in this movie stand out quite a bit.
The American remake of Seven Samurai. The two movies are quite different in style, actually. Not much time was spent delving into each character, but Coburn, Brynner, and Bronson's performances were strong and memorable.
Ian McKellen as Gandolf
The Great Ian McKellen. A veteran of the stage, and member of the Royal Shakespeare Academy (with Patrick Stewart and David Suchet in the 80's). I hope Ian McKellen never retires, and continues to give great performances.
Alec Guinness as Colonel Nicholson
Alec Guinness was a world famous actor decades before he appeared in Star Wars. He also co-starred in Lawrence of Arabia and Doctor Zhivago, which were alternatives to this choice.
Gene Hackman as Jimmy 'Popeye' Doyle
Gene Hackman is one of those guys who are too good to be type-casted. I could have chosen a few different iconic roles of his, but I chose this one, because many people have seen it.
Mia Farrow as Rosemary Woodhouse
Who wasn't somehow affected by this movie after seeing it? Imagine if someone else had been given the role? ... yeah, I can't either. Mia Farrow had the natural innocence, with the acting talent to keep us following her through the end of the movie.
Harrison Ford as Dr. Henry 'Indiana' Jones
Harrison Ford really threw himself into being Indiana Jones. He made kids around the world want to study Anthropology, carry a whip, and wear a brown fedora. It was both the image, and his tough but likeable portrayal of the character that made a memorable impression upon the movie.
This is where it began. Sigourney Weaver played flight officer aboard a deep space mining vessel. Her stress and fear were palpable, and added tension to the scenes. In combination with the rest of the cast, Sigourney Weaver's performance is both dramatic and believable.
Arnold Schwarzenegger as the Terminator
Arnold was a veteran of the screen at this point. But his portrayal of The Terminator was more impactful in this movie than the first, and the story gave the character a third dimension.
Linda Hamilton as Sarah Connor
Linda Hamilton really did a great job as Sarah Connor. She did a great job of transforming herself into a doomsday prepper, a very different person than she was in the first movie.
Edward Furlong as John Connor
Edward Furlong may not have much of a career today, but his role as John Connor will always be remembered as one of the best portrayals of a child character in recent memory.
Robert Patrick as T-1000
This guy was scary. No emotion, no hesitation, no... bones? The T-1000 is the scariest Terminator. He can look like anyone, and absorb your bullets. A walking nightmare to fight against.
Rutger Hauer as Roy Batty
Rutger Haeur's portrayal of the replicant Roy Batty felt like a combination of genius and insanity. Many of the characters in the movie are memorable, but this was the strongest performance, and perhaps the best of Hauer's career.
Charles Bronson as Paul Kersey
Charles Bronson was a veteran actor before taking this role, but this movie helped to make him famous as a leading actor. Not his best work, but he carries the role well.
Bruce Willis as John McClane
This movie really propelled Bruce Willis into the action movie world. Personally, I liked him better in moonlighting, but he does have a strange almost clumsy way of outsmarting and killing the bad guys.
You may ask "why choose Doctor No. ?" Easy. If this movie tanked, and Sean Connery wasn't convincing as James Bond, there would be no 'From Russia With Love', 'Goldfinger', and perhaps no James Bond movie franchise at all. This movie started the James Bond movie franchise as we know it today.
Toshiro Mifune as Sanjuro, the Wandering Samurai
A great role for Mifune, as the wandering Samurai who decides to become involved in a war between two crime families. This movie was the inspiration for the 'Fistful of Dollar' movies.
Donald Pleasance as Dr. Sam Loomis
Donald Pleasance has a talent for understatement and the ability to communicate emotion without using words. This is not the best movie he was in, and probably not his best performance. But, he was in at least four Halloween movies, so he is part of the franchise. You should watch him in THX-1138.
Sylvester Stallone as Rocky Balboa
This is probably Sylvester Stallone's most memorable movie role. He wrote this story (based off a real boxer), and did a great job portraying a local punk turned local hero.
Carl Weathers as Apollo Creed
Carl Weathers really convinced me that he was a trash talking, athletic fighter in this movie. A really great performance, and good contrast with Stallone's character.
Bugress Meredith as Mickey Goldmill
Many a parody has been made of the character Mickey. But that's only because the world class actor Burgess Meredith gave such a memorable performance.
This isn't my favorite movie, but no one can deny it was a memorable performance by Mike Myers. Playing both Austin Powers and Dr. Evil, Myers was able to convincingly be both the hero and the villain.
This list is a work in progress of some of the most memorable roles in movies. I'll add more movies when I have time, although I'll try not to make this a 100 item list. Many actors are not defined by a single role, so you may see someone appear more than once. In some cases, I'll offer up and alternative to the choices that I made.