Where did you see season 4? When I watched it on Netflix there (I think) was only up through season 3, or whichever season where Jesse kills Gayle.
I got into that show and several others due to this thread, The Tudors, Mad Men, The Killing to name a few. TYP! (Trust Your Peeps)
It's available on DVD here in oz, I actually downloaded it through iTunes on to my iPad and watched it all on my way to work.
Brilliant show. On the recommendations of everyone I've decided to get into mad men after I finish misfits