Mad Men (favorite alltime show)
Friday Night Lights
Top Gear (UK of course)
You said top 6 right? Also, I can already tell Game of Thrones will be knocking somebody out of my top 6 in a few years.
Edit: WTF? I am the only person that listed Mad Men? I don't normally do this, but people you need to drop whatever you're doing and spend the next few days watching every episode.