Spartacus
Definitely a bad start. I tuned in out of curiousity to see some (bad)ass 300 ripoff and maybe rub one out if the sex was really hot. Instead it was just boring, and not at all well written or well done. I remember laughing, thinking how full of crap Andy what's his face was, because during one of the behind the scenes features Starz bombarded the air with, he said how great the script was. The script was awful. I never watched the second episode.
But about a month later I had heard that it was getting a little better.. and by the time the 6th episode was about to air I caught up and somewhere in those first 6 episodes the show goes from crap to cheap entertainment to pretty damn fantastic and then barrels through the second half of the season with nothing less than pure brilliance and some of the greatest writing and performances in the history of television.