Last year I did the first 9 years of Stargate SG-1, but it wasn't a "sit down and watch 'til it's done" thing. Took about 5-6 weeks. Each episode is about 43 minutes and without commercials, so it goes by pretty quick. Four episodes was a nice 3 hour evening. Likewise with Star Trek: Voyager and Star Trek: The Next Generation.
We've been running a similar marthon this winter, watching the X-Files 9 seasons from start to finish. Probably going to take us closer to a couple of months to finish since I'm away most weekdays now. Since I had not watched any episodes since it left the air a number of years ago, I had forgotten what a well written show it was with all the continuous and intersecting story lines. Some great LOL moments too!
