I started watching right before season 2. Since Breaking Bad, it's probably been the only show I have to watch every week when it airs. I have them all on DVD and now that they're all on Netflix it's on a constant rotation. I've watched the whole series so many times.
Season 5. So many classics. And so many more to go. Season 10s premiere didn't skip a beat. My favorites seem to be when they just absolutely binge drink and have no control of themselves lol.