Hmm. Buffy Season 5 in a weekend was my introduction to the show. Firefly took me 2 days, I guess. My So-Called Life was a single sitting, Freaks and Geeks was two. I once did two seasons of That '70s Show at once, and Alias Season 1 was watched at least 6 episodes at a time. Though Gilmore Girls Season 1 took me a full week, that was only because of Netflix waiting time - each set of three discs was watched in 1-2 days with a waiting time in the middle. And the last half of Once and Again Season 1 took me less than a day.
So, yeah.