Showtime's sympathetic serial killer provided the most illicit entertainment for viewers in 2011, with Dexter narrowly edging out HBO's Game of Thrones for the top spot in Torrent Freak's annual roundup of the most pirated television shows of the year (full list below).

There were 3.62 million illegal downloads of Dexter this year, as compared with an estimated 2.19 million legitimate viewers of the show in the U.S., according to Torrent Freak, which compiled the list from several sources, including reports from public BitTorrent trackers. Game of Thrones, with 3.4 million downloads of pirated episodes to an estimated 3.04 million legit U.S. viewers, was the only other show in the Top 10 list with illegal downloads that exceeded the legitimate audience.

Illegal downloads of Dexter actually dropped off by about 260,000 from 2010, Torrent Freak reported. Last year, pirated downloads of both Lost and Heroes actually exceeded 5 million, according to the site, but both of those popular shows ended in 2010, while alternative, legal sources for television content have also appeared to cut into the number of illegal downloads.

A massive crackdown on people who use torrents to swap pirated content in 2011 may provide a further explanation for why the overall numbers of illegal downloads appear to have fallen fairly substantially in the past year.

"Although the years of exponential growth in download numbers have passed, episodes of the top TV shows are still shared among millions of people," Torrent Tracker reported. "Despite the fact that Dexter and runner-up Game of Thrones have more downloads than television viewers in the U.S., the overall number of TV show downloads is leveling off.

"The percentage of TV show downloaders, from the U.S. in particular, has steadily declined in recent years," the site concluded. "This is in part thanks to alternative viewing options such as Hulu and Netflix. In other regions, such as Australia and Europe, the demand for U.S. TV shows remains strong."