BSG got cancelled?! How in the world did they build up to such a fantastic ending?! Five seasons of pure awesome! I think that must be an incorrect fact. FireFly got cancelled, but BSG?! Really?
BSG was only 4 Seasons. Yes, it intended to be at least 5 seasons, but after the first half of S4 (Or maybe when S4 in it's entirety was commissioned) they were told to wind it up by 4.20. It wouldn't have gotten that long, except for the prestige, because it was a "Critic Darling" and they gambled that the prestige would improve their brand image., so, they supported it longer than they normally would, to give it a chance to grow, which it never did.
Whedon's Dollhouse, had an awesome finish being cancelled after only 2 seasons, because he was told in enough time to wrap it all up (Though, the 13 episode season 2 could easily have been a 20+ episode season, or even 2 13 episodes seasons)