Complete and utter freedom like The Legend of Zelda with useful, not useless crap and lotsa proper dungeons. And please Aunoma, we don't need an old man to point out large, obvious landmarks rising in the distance. We aren't stupid. We can't possibly miss it.
I think BOTW's level of freedom matched the open expanse of the game perfectly. If BOTW2 is gonna follow the same structure then I'd be happy for it to allow as much freedom as BOTW. If it's going to be more story driven but still have a large map the I think ALBW style would be better suited, with set objectives but the freedom to attempt them in any order.