Some shows, like Monk and Supernatural, can clog things up because I fell way behind and have taken advantage of various marathons to get myself back up to speed. And then you have a show like the U.S. version of Being Human, which builds up because it’s not bad enough for me to go ahead and be rid of it altogether, but is low enough on the totem pole that I often put it in the “next time” pile when I’m deciding what to watch next.