I want to say Firefly, I want to say Dollhouse, buuuttt...
They ended very conclusively, I wouldn't want to take away what's been done, emotional value starts wavering when you retcon things.
So I don't think I'd ask for either, I'm happy to have the endings they had, I'm sad they are gone but pleased that even though they were brief they were brilliant.
That's enough.
Instead I'd like to request the ability to request something new with that same spark.
As truly something new to add to the list of things I'll wish I still had long after they cancel it is worth far more to me then hurting the things I love to bring them back.