Although I would not rate it as the best series, or even in my top 5, I am really enjoying "Burn Notice" at the moment. McGyver, spies and comedy all mixed into one series. It is definitely formulaic, but still some light-hearted fun after a busy day at work.
The two series we have been devouring in the last couple of years have been "Homeland" and "Game of Thrones". GoT is deviating from the books a little, especially overlapping books 2 and 3 for the second series and I am presuming books 3 and 4 for the third series, but it is still good entertainment. Unfortunate when they accidently include beheaded ex-PoS in an episode, but good unintentional advertising I suppose.