Best Non-Comedy:
1. Game of Thrones (and not even close)
2. The Wire
3. Breaking Bad
Best Comedy:
1. Arrested Development
2. 30 Rock
3. South Park
Honorable Mention: It's Always Sunny
And I won't put this in best series of all time, but best series finale was The Shield. No show I've seen closed out as well as they did. That ending stuck with me awhile.