I can't pick one so I'll say which out of the choices and maybe add one or two.
New Girl - so funny, I wouldnt say its the best, but it sure is a 'pick me up' when your feeling blue!
Terra Nova - Meh.. It's ok, wouldn't say it's the best. Pretty predictable.
The Big Bang Theory - Possibly the funniest tv series ever. Sheldon <3
The Walking Dead - Amazing.
True Blood - Amazing.
Dexter - Addictive and genius.
How I met your mother - Its ok