Steve Buscemi opened his episode of SNL by remarking on his good fortune in finally making the leap from creepy character actor to leading man (in HBO's "Boardwalk Empire").
While having a specific look and/or mannerisms may be a boon in terms of booking memorable, supporting roles, those very things that make one so castable can also leave an actor permanently relegated to the TV and movie sidelines. So Buscemi's breakout at this point in his career is certainly an inspiration to his peers.
In fact, the cast of SNL is inordinately populated with "characters," all of whom wanted to know how Steve did it. The star found his monologue interrupted by all of the classic archetypes: the clumsy best friend in romantic comedies, the magical African-American who gives white people advice, the party guy who wants to go to Vegas, the helpless woman in a horror movie, and more.