For a long time she was Peg Bundy with the swishy hips and quick put-downs from Married…with Children, then she morphed into the cool, one-eyed alien, Leela, of Futurama.
Look at Katey Sagal, getting in a Sons of Anarchy reference in her answer, totally unprompted.
But, as soon as she took the role of Gemma Teller Morrow on Sons of Anarchy, she cemented herself in people’s minds as the protective schemer and manipulator.