You can write what you watch generally. It does not have to be new series or whatever is on TV right now. And yes, it does not matter what it is. It is your own business, so just write, no one will laugh.
Here is my list:
Warehouse 13
Stargate Atlantis (not these days, 2007-08 after Heroes while sitting before the new Crisis Core)
Heroes (not these days, 2008-early 10 or so while sitting before the new Crisis Core)
NCIS
Friends
The King of Queens (not these days, like from 2003-06 or 07 every day)
How I met your Mother
The Big Bang Theory
Scrubs (often but less than the other two mentioned above)
Detective Conan
Dragon Ball
One Piece (a bit while waiting for Conan)
Ugly Americans
Disney's Kim Possible (not these days, 2008-09, 2012)
Of course also many other series but not all the time, just in case there is nothing else. Earlier I also watched Spongebob Squarepants but when new episodes were released I was disappointed by many of them so I don't really watch it anymore. I also started watching Futurama last year but the problem is most of the time they only show the same episodes in a short time.
Some other series I have watched earlier and which are not on TV anymore:
The Fresh Prince of Bel Air
Pokémon (only on the weekends on TV now)
Sailor Moon
Inu Yasha
Yu-Gi-Oh! (only on the weekends on TV now
Avatar The Legend of Aang
Avatar The Legend of Korra