If there is one thing I have never actually wanted, it is to be an astronaut. I may be fascinated by space by the pure fact that we know so little about it, but the myriad ways of potentially dying in space haunt my brain, even though I'm not at all in a position to be jettisoned out of the atmophere. To make a long story short, in this scenario where I am an astronaut, trying to envision a perfect day ultimately boils down to "whatever results in the least chance of me dying alone in the inky blackness that makes up most of the Universe."
I've certainly spent countless hours looking at astronaut-taken photographs and can appreciate the beauty of the universe from an astronaut's privileged position. But my understanding is that an astronaut doesn't simply "hang out" in space: there are things to do, things to maintain, and things they are required to do every day in order to survive in what I would only describe as a potentially hostile environment.
For anyone not aware, if you're in space and something catches on fire, you can't just call the fire department. If you hurt yourself, you can't just call an ambulance. I'm not really Good at Things(tm) so maybe if I were, the idea of free-floating away from all conveniences wouldn't be so all-consumingly terrifying.
I could go on for a long time about the terrors of space and why I won't want to go up there, but I guess I'll just say this: if I were an astronaut, my perfect day would be the one where someone at NASA realized their mistake and took away my astronaut license, leaving me to stand on solid ground and deal with the potential disasters inherent in living on Earth.