I guess most of you won't agree with me, but I'd like a full reboot of the series made in 2D, with indie-style (or Animal Crossing-esque) graphics and no voices.
Specially if that way we could get all the missing or reworked chapters (the boat one, the Shanghai one, the train one, etc.). And of course the rest of the story in full, with no compromises. The music, dialogue, script, minigames, arcades, economy could still be there as well.
Ideally that would be a side series and could be released alongside regular Shenmue games