Dr. Sam Loomis

Dr. Sam Loomis as portrayed by Donald Pleasence in John Carpenter's 1978 classic "Halloween."

The part of Dr. Sam Loomis was originally offered to Peter Cushing and then to Christopher Lee (Lee would later say it was one of his greatest regrets that he turned down the part) both declined the role due to the low salary, and in my mind it was a blessing in disguise. As much as I love Cushing and Lee, I can't picture anyone other then the great Donald Pleasence as Dr. Loomis.

Named after a character in Alfred Hitchcock's "Psycho" Dr. Sam loomis is the ultimate modern day Van Helsing obsessed with his duty of tracking down the evil he knows will strike again...

An interesting piece of trivia:
Donald Pleasence's daughter had watched Carpenter's "Assault on Precinct 13" and liked it, thus encouraging her father to star in Halloween. Pleasence has said that this was the sole reason he took the part.