Don't watch too much TV, But here are the ones i enjoy.
Dexter - One of the best TV series i have seen. Great plot with lots of twists. John Lithgow was really good in the last season.
Fringe - Im only into the 1st season at the moment but find it quiet interesting
The Universe - Very interesting. Lots of eps to choose from
How I Met Your Mother - Started watching this late last year, i initally thought it would be garbage but im glad i sat down and watched it. Very funny and you can pretty much watch any episode without having to know the background of the show.
Entourage - Seen all eps so far. Ari is by far the funniest. Everyone i know enjoys this series and the eps are quiet short at 22mins.
top gear is the show i least enjoy (waits for the hate)

and now there is a Aussie version