Can't really order them but: 

Utopia 
In the Flesh
Avatar The Last Airbender/Legend of Korra 
True Detective
Supernatural (Seasons 2 - 5, the rest of the seasons are good but not in the top 10 list)
Game of Thrones
Hannibal
House of Cards (UK)
Being Human (UK)
Sherlock
Star Trek: The Next Generation 

And Honourable mentions go to Smallvile, Silk and Fullmetal Alchemist: Brotherhood (literally just started watching this but love it already).