7. Frank Costanza
Best-known episode: "The Strike"
George's highly combustible father. Co-creator of the mansiere (or "the Bro") and inventor of "the stop-short." Former army cook, fluent in Korean; once met the Rev. Sun Myung Moon ("a hell of a nice guy"). Next to Newman, Frank Costanza – first portrayed by John Randolph, but made famous by Jerry Stiller – is unquestionably the star of the Seinfeld supporting cast, so choosing his best episode is impossible. Instead, we'll go with one that best sums up everything we love about him: "The Strike," a Season Nine standout in which Frank rekindles Festivus, the anti-Christmas he created decades earlier after beating a man with his bare hands. Whether he's berating his son ("You don't need glasses! You're just weak!"), engaging in the airing of grievances or challenging George to a wrestling match, this is Frank at his most unhinged and irrepressible…which is just the way we like him. JAMES MONTGOMERY