This got me to thinking though, what if Supernatural kinda ends like this? What if we see a similar situation happen between Sam and Dean like what we saw between the Buffy versus Angelus storyline? Say, we have a scenario where Sam says yes to Lucifer, we'd then would have to see Dean trying to deal with finding alternative ways of defeating Lucifer without harming his brother and without giving his consent to the angels, about understanding his destiny and where to go from there and so forth. Or an inevitable situation where one of the brothers has to die no matter what happens. Just an apocalyptic showdown between brothers, this has been something I've thought about even before the announcement of another season, because I feel like it would be a perfect way of ending the show.
But then again, I tend to think of my fandoms on an epic scale, particularly those with heavy mythologies and strong character arcs, which is why I gave my concern over the sixth season.
Needless to say, rewatching Buffy has given me a new perspective and has lessened my worries somewhat about a SPN sixth season, in which they can have some comedic stand-alone episodes just as long as they don't lose track on character stories and giving us a resolution towards everything we've learned over the course of the entire series and give us a frakking epic ending to it all.