Mulder and Scully, Sam and Diane, Lucy and Ethel… just their names conjure up plenty of great TV memories. ABC is celebrating the small screen’s all-time best pairings with this "TV's Most Dynamic Duos," ranking the 30 best duos in TV history. Along with the countdown, host Robin Roberts will bring us all-new interviews with stars like Megan Mullally, Edie Falco, and Norm and Cliff themselves, George Wendt and John Ratzenberger. (Those guys get our vote.) Who will be No. 1? Find out on Sunday at 9 PM on ABC.