1. Kyubey becomes hope itself, erases every witch in history. 2. World is rebuilt, Kyubey no longer exists. (But Incubators still do.) 3. The main cast lives happily ever after, having never met Kyubey, until about 10-15 years later they are all killed randomly by some demons. Other girls still become Puella Magi but they never learn about it. Also Kyubey now owns Puella Magi Hell.
Alternatively:
2. World never gets destroyed in the absence of uberWitch!Madoka. Stuck in a cycle of collecting grief endlessly, Kyubey becomes the force to counter entropy itself. 3. The main cast lives, having never met Kyubey. No longer profitting from creating Puella Magi or having to fear entropy, the Incubators leave the planet. Humanity is left to fend for itself the best it can. 4. Best end?
How can a being that can only close its eyes and open its mouth make such good reaction faces?
Mahou Shoujo Madoka☆Magica~FIN~With your ownSuper Happy End Chapterhandspast and future, I want you to erase every Witch...I want to erase every Witch before they are born!In all the worlds,Eh?Coming soon: with the clumsy little witch Madoka, the slightly perverted Homura and the others, the new heart☆pounding☆heartful love comedy called "Mahou Shoujo Madoka ☆ Where?"!