This is easy.
2. The Wire
4. The Walking Dead
5. A Game of Thrones
Such a good list, wouldn't change a thing.
If my list included TV shows that are no longer being made, I would have to add:
Deadwood - Such an amazing TV show, so many good characters which made every minute of each episode enjoyable. It's a shame it only got 3 seasons and ended the way it did, I hate when a TV show gets cancelled and doesn't have one last episode to tie everything up.
The Shield - Vic fucking Mackey!! The series finale for this show is by far my favorite finale for any TV show, such a good episode to end the series IMO.
The Wire - Snoop is one of the best TV villains of all-time. I think alot of fans of this show will agree that Season 4 was fucking awesome and the best season of the show.
Generation Kill - It's unlike Band Of Brothes and The Pacific in where there aren't very many scenes that have them engaging the enenmy, it's more on the whole effect it has on everybody but it is still an amazing "war-time" TV show.
Captain Planet/Captain Planet and the Planeteers - One of the best super-hero themed cartoons of all-time, this show is so underrated and does NOT get the love it deserves.
"I Love" Series - I really enjoyed the I Love series, especially I Love The '80s & I Love The '70s.... it was awesome to see the commercials for all different types of stuff from back then.
Honorable Mentions: Rescue Me, Curb Your Enthusiasm, Band Of Brothers, The Wonder Years, Roseanne, GI JOE: A Real American Hero, Entourage, Torchwood, Saved By The Bell, and Boy Meets World.