Cover and back cover by Frank Brunner for Marvel Treasury Edition #6, 1975.
Dr. Strange began his own title picking up with issue 169 of what was Strange Tales. It continued (complete with an ill-advised costume change) through issue 183, cover dated November 1969. He would later get his title again, beginning this time with issue #1 in June 1974. Here's a few of the more interesting cover from his first run.
Dr. Strange #173, October 1968. Cover by Dan Adkins.
Dr. Strange #178, March 1969. Cover by Gene Colan.
Dr. Strange #179, April 1969. Cover by Barry Windsor Smith.
Dr. Strange #180, May 1969. Cover by Gene Colan.
Dr. Strange #181, July 1969. Cover by Gene Colan.

Doctor Doom by John Buscema, n.d.

Psychoanalysis #1, April 1955. Cover art by Jack Kamen.

Dr. Octopus vs. Spiderman by Jim Mooney, n.d.

Dr. Solar: Man of the Atom #20, July 1967.

M.D. #4, November 1955. Cover art by Johnny Craig.

Cover for Dr. Strange Portfolio by Michael Golden, 1983.

Ben Casey daily by Neal Adams, January 4, 1966.

Painting of Dr. Kildare, unknown artist, n.d.