Then you're watching the wrong show. GoT has consistently sided with the idea of a dirtier, more morally gray world where good people get shit on and die horribly while terrible people rise and prosper. I just can't see this show having an ending that doesn't fit that theme.
Personally, I expect Jon to kill Dany (not by choice, but out of necessity or self-defense). Then be offered the throne. And for him to just throw up his hands and say "Screw it. No. I've had it with you people. Peace out!" And walk away. Watching the noble Jon Snow, who has never turned down a call of duty, just turn his back and walk off into the sunset to try and be happy with what's left of his life is about the only happy ending I can hope for.