The perfect ending for Once Upon A Time would be for us to get a sequel or movie called Twice Upon A Time. Just kidding.
But the real happy ending would go as follows:
1. Regina and Robin Hood are happily married, and have a kid. (Regal Arrow Endgame)
2. Emma reunites with Neal. (Swanfire Endgame)
3. Emma and Neal move into the mansion with Regina and Robin Hood, that way Henry can have both sets of his parents. (Come on, we all know Regina’s five bedroom, three bath house is enough for them)
4. The EF is completely destroyed by a darker force(I agree Chernabog), but those who survived the curse are brought to Storybrooke beforehand.
5. David and Snow buy themselves a nice cottage home across the street from Regina and Robin, and the Charming Couple have a baby boy.
6. Rumple, sacrifices his dark powers to save either Belle or Neal, and dies a noble man. BUT Belle kisses him with TLK, thus bringing him back completely whole so he can walk without that cane! Captain Hook and Tinkerbell get together, and sail the worlds occasionally dropping into Storybrooke every week for about four days.
7. Regina and Snow to repair their mother-daughter relationship. Hopefully Snow will call Regina mom someday, and David can jokingly call Regina his “mother-in-law” while Emma calls her Grams. (She’s the family stone! Her and Rumple that is!)
8. Henry will hopefully be around 18 at this point, and is getting married to a girl his family approves of. Maybe someone who once was misunderstood and bad, but he turned her good.
9. For our gang to defeat the number one evil Chernabog, and live in Storybrooke which becomes a gateway between worlds.
10. For The CharmMillsStilskins to all live happily ever after.
11. Series Finale: “Ever Happy”: The characters all prepare for Henry’s wedding.
"If you go as far as you can see...you will then see enough to go even further." - Finn Balor