I was bought the boxed first four seasons of this for Christmas. Unbelievably it's never been shown in it's entirety on UK TV. First series disappeared without trace, series 2 and 3 were I think on 5USA around midnight. I think it must be the best ever USA series ever made...better than The Sopranos, The Wire, West Wing etc. It's riveting viewing, engrossing, dark, hilarious, thoroughly amoral, and ....just amazing.
It's almost impossible to resist playing the next episode. It's so good that I've had to suspend my current viewing of the Being Human series 1-4 box set. The fifth and final series is currently showing in the US. - not available here until July.