Forbrydelsen (The Killing)
Seinfeld
Twin Peaks
Bonanza (can't believe noone has mentioned it earlier)
The Simpsons
Corleone
In no particular order(but if I'm forced to chose one, it'd be The Simpsons).
The first one is Danish (has it's own thread in here), the last one is Italian, based on the life of Mafia-leader Toto Riina. They're both brilliant, well played two/one season series.