As the show enters its 10th year, Henry has his 21st birthday and a Greek or Celtic god or some friendly aliens come and explain to Henry that they have been watching, and that he is the Final Savior, who will rescue all our worlds from the curse and demon we know nothing about as yet, even now---the terrible powerful SOB who took magic away from this world and trapped it all in the worlds of OUAT.
As the show ends its final season some years later, after great sacrifices and epic struggles on the part of all cast members, Henry is victorious. The submerged continent of Atlantis/EnchantedForest/Neverland arises and, planes circling, officials screaming hoarsely into their phones, dragons soaring in the skies, the 21st Century awakens to a new world. Henry himself is not celebrating---his dragon has been badly injured, and his family is missing. Then we see the Jolly Roger, bedraggled, sails torn; it has survived the tidal waves and Emma/Hook and the Charmings and Regi/Hood and Bell/Skin and the kids are safe.
As lengthy credits in fancy script scroll by, we see vignettes of people discovering little bits of magic--fairies in the garden, mermaids splashing around the Statue of Liberty, an elf explaining to someone in a bathrobe that his contract requires a bowl of milk be set out every morning, etc...
That's what I want to happen.