I watched the first few seasons, but then when it got plot-driven I missed a few episodes and didn't feel like I could keep watching unless I watched all of it - and at that point I'd lost a bit of interest in it because I tend to prefer "monster of the week" type shows. I started watching it again from the start, but now I don't have access to the same copies as I had before, so I still haven't caught up with it
(on the rewatch, I was half-way through the episode with the guy who could tell people to do what he wanted - season 2, I think)
Annnnnd now I can never come into this thread again because it will be full of spoilers :I