Ringworld

Don't think it has aged super well. Would give a 2.5 if I could, but since I can't, I'll settle for a 2. It's classic big-idea sci-fi from when a time something like a ringworld or a megastructure was still novel, but ignoring that, it doesn't really have anything else interesting, and it seems to barely explore its key concept.

The ringworld idea is fantastic, but the book just uses it for some mediocre adventures. Sex scenes were horrendous.