An episode you've watched more than 5 times
While I haven't kept count, there'd be several episodes of Star Trek, M*A*S*H, The Muppet Show and Firefly that would qualify... and at least one of Batman: The Animated Series.
I'm not a big fan of Christmas specials, though there are a few movies that I think capture the spirit of the season - such as 'It's a Wonderful Life', 'Die Hard', 'Trading Places', 'The Addams Family', 'The War Game', and especially 'Brazil'. Every December, I promise myself that I'm going to re-watch at least one of these... but I invariably run out of time, and settle instead for watching 'Holiday Knights', which packs three stories and an epilogue, four villains (Harley and Ivy, Clayface, and Mark Hamill's gleefully insane Joker), Harvey Bullock as Santa, and some jokes that must have zoomed over the heads of any kids (and censors) into less than a half-hour.
Day 01 - A show that should never have been cancelled: The Twilight Zone
Day 02 - A show that you wish more people were watching: Media Watch
Day 03 - Your favorite new show (aired this TV season): Doctor Who
Day 04 - Your favorite show ever: Star Trek (the original series)
Day 05 - A show you hate: Disinfotainment
Day 06 - Favorite episode of your favorite TV show: 'Errand of Mercy'
Day 07 - Least favorite episode of your favorite TV show: 'Turnabout Intruder'
Day 08 - A show everyone should watch: 'Dark Side of the Moon'
Day 09 - Best scene ever: Funeral scene from The West Wing's 'In Excelsis Deo'.
Day 10 - A show you thought you wouldn't like but ended up loving: Top Gear
Day 11 - A show that disappointed you: The Twilight Zone's 'The Star'
Day 12 - An episode you've watched more than 5 times: Batman the Animated Series, 'Holiday Knights'
Day 13 - Favorite childhood show
Day 14 - Favorite male character
Day 15 - Favorite female character
Day 16 - Your guilty pleasure show
Day 17 - Favorite mini series
Day 18 - Favorite title sequence
Day 19 - Best TV show cast
Day 20 - Favorite kiss
Day 21 - Favorite ship
Day 22 - Favorite series finale
Day 23 - Most annoying character
Day 24 - Best quote
Day 25 - A show you plan on watching (old or new)
Day 26 - OMG WTF? Season finale
Day 27 - Best pilot episode
Day 28 - First TV show obsession
Day 29 - Current TV show obsession
Day 30 - Saddest character death