HBO has all of the best shows on TV right now.
AMC has one great show (Mad Men), one really good show (Breaking Bad) and one average show that varies in quality (Walking Dead)
On HBO right now there's three great shows (Treme, Boardwalk Empire, Game of Thrones) and one very good one (The Newsroom). I hope Curb will make a comeback too.
Then when you compare what HBO has done with The Wire, Sopranos, Deadwood, Generation Kill, Band of Brothers, Six Feet Under, etc etc, it's an absolute no contest.
Not sure anyone will ever come close to touching HBO. They're the kings of TV by such a large margin it's ridiculous. Wish I lived in America to have it...