My favorite thing to talk about, quote, watch, etc. is How I Met Your Mother. Its gross but I love it.
Glee is another one of my disgusting obsessions. I love singing the songs, watching the show, obsessively talking about the characters.
Another really good Glee site is this one.
The Buried Life is another one of my favorite shows. It has an absolutely amazing message.
In terms of general awesome television discussion, Television Without Pity is the best.