DON'T MISS: "SNL 40th Anniversary Special" - Party on, Garth! The sketch show that introduced us to so many future comedy stars and memorable catchphrases, celebrates four decades of hilarity. Many of the brightest "Saturday Night Live" alums are on the guest list, including Mike Myers, Tina Fey, Chevy Chase, Adam Sandler, Will Ferrell, Molly Shannon and even Eddie Murphy, who hasn't graced Studio 8H since 1984. Well, isn't that special? 8 p.m. Sunday, NBC.
SUNDAY: On "Downton Abbey," Mary loses a suitor, which is really extra sad because they didn't have reality TV dating shows back then. 9 p.m., PBS.