I stayed up from a Friday morning thru a Monday afternoon once without sleep and watched the entire marathon of Red Dwarf on BBC America. All eight series/seasons. Beat that, anybody!
Usually it takes me weeks just to watch a season of a show. I started watching Sanford & Son from season 1 in late Nov and I'm now on the first DVD of Season 6. That's about as fast as I go. I once spent about 2 years watching Xena Season 1 since I knew I didn't have the money for Season 2 I took my time.