Certainly different games lend themselves better to low-prep campaigns than others. Shadowdark, for example, works really well. It is full of interesting tables that keep the game fresh and produce results that can build out the world as you go. Plus the statblocks are simple and the rules are...
Other frames:
Journey to Horizon: "bread and butter fantasy" but complexity 4. Hexcrawl in DH. 30 to 40 session Journey campaign. Emerging from a "fallout style vault" after 1000 years, and you have an old map of the world.
Adversaries! Gremlin Warband. Something that looks like a bullette.
New environments include a masquerade ball.
Campaign Frames:
C&P Reign of the Weredragon: all about diving into a dark fairy tale. "Under the shadow of this dragon's wings wherever you go in this kingdom."
Session 0 the whole...