Dexter

I have seen a series which I consider a strong candidate for the "Best Series Ever" award: "Dexter". I utterly enjoyed it, as it is a great mix of drama (in a higher percentage) and comedy. 

Dexter Morgan

Dexter is a drama about a forensic (Dexter Morgan) who works for the Miami Police by day, and is a reckless serial-killer by night. All along its eight seasons, it shows how his life evolves and how his actions affect him and the ones he loves. It is an almost perfect combination between drama and comedy, very vividly portrayed by its great cast. It is really thrilling and it has various touching scenes. The only drawback I can find (to it) is that it is a bit clichéd in its last two seasons, as it seems that the screenwriters lost a bit of their imagination.

In conclusion, I strongly recommend it for everyone who likes a good drama, despite its bad things, which are almost none.