It’s Always Sunny In Philadelphia (FX, 10 p.m.) — Season premiere. By my count, last year had four instant classics (“The Gang Goes to the Jersey Shore,” “Chardee MacDennis: The Game of Games,” “How Mac Got Fat,” and “Thunder Gun Express”), so there’s no point in worrying that It’s Always Sunny will suddenly drop in quality during season eight. As long as Frank and Charlie are around, it won’t.
30 Rock (NBC, 8 p.m.) — The long-awaited “Bryan Cranston as Kenneth’s mom’s friend Ron” episode. Also, Catherine O’Hara, who is a Canadian treasure, like Baby Goose and Barenaked Ladies.
The Big Bang Theory (CBS, 8 p.m.) — Guest star Margo Harshman, from Even Stevens, has grown up nicely.
The Vampire Diaries (The CW, 8 p.m.) — Season premiere. I’d be disappointed in the world if The Vampire Diarrheas doesn’t exist. Someone braver than I can Google it and let me know.
Vice Presidential Debate (Lots of channels, 9 p.m.) — I know Biden vs. Ryan is important and all for our country’s future, or at least it is now because of these photos (and for quoting Veep, you stupid little, croissant-loving f*ckers), but still: I WANT MY PARKS AND RECREATION ON THANK YOU VERY MUCH.
LATE NIGHT GUESTS: Lucy Liu and Rob Corddry on Letterman; Terry Bradshaw and Grizzly Bear on Leno; Kevin James and Ezra Miller on Kimmel; Christina Applegate, Nick Offerman, and Jackson Browne on Fallon; Paul Thomas Anderson on Stewart (!); and Chrystia Freeland on Colbert.