Most fictional worlds are rife with danger or ruled by oppressors, so I think I would want to visit The Night Circus (of *The Night Circus* by Erin Morgenstern). I would visit as many of the attractions as I could reasonably do in one night without rushing or failing to take in the many subtleties that make The Night Circus what it is. I imagine I would only be allowed a single night there, but if I could visit more than once I would.
Once, at the end of a conference, I walked into the bathroom of the suite I was staying in to find that the walls and mirror were covered in small splashes of blood! No pool of blood—just hundreds of small splatters, everywhere. Whose blood was it? What happened to them? Why did it happen in my room?
(I eventually found out the answers to these questions, but the mystery is far more interesting than the solution.)
Peter Wimsey and Harriet Vane, from Dorothy L. Sayers' Peter Wimsey series of mysteries have my aspirational relationship: two smart, independent people who sharpen and amuse each other and will never settle for being less than equal partners.