- Valery the Russian and his brief but memorable performance in "Pine Barrens", one of the most acclaimed episodes of the series.
- Lou Di Maggio and the Atwell Avenue Boys.
- Dr. Krakower, an aged Jewish psycho-therapist that Carmella sees in "Second Opinion"; he's in exactly one scene. He accurately tears apart her delusions of Tony being "a good man", and offers some of the most memorable lines in the series.
- And of course, the unnamed patron in Holsten's in the final scene credited as "Man in Members Only Jacket" (or MOG to the fans). He may not have any lines, but the fans who do believe that Tony was killed in the final episode have this man to thank.
One Scene Wonder / The Sopranos