I am continually watching it through.
Have gone through all seasons from 1 to 4 3 or 4 times so far, and I'm at episode 20 of season 4 currently.
When I finish it, I'm going right back to the start, season 1, episode 1, and then it begins again (and while season 5 is on I'll still be watching through from S1 to S4, then I'll make it S1 -> S5 )
It's especially good to watch while eating breakfast, takes me under 20 mins to have breakfast, and while I do it I watch Scrubs, then I laze around for a few minutes while Scrubs finishes.