Not a house guest but I was rushed into hospital as an emergency, house left like a crime scene so MIL offer DH to take his key and clean up so it was ready for us coming home. She did a great job at cleaning, no stains or anything which was impressive on a white carpet. Except... she went through our badroom draws (nothing to do with anything) took out all our 'adult supplies' (condoms, massage oil, dildo etc...), organized and rearranged them 😱.
Other than that I found most house gusts just run of the mill rude, I had several friends who pretended they couldn't grasp the concept that the kitchen/bathroom/bedroom/conservatory does not class as OUTSIDE in our non smoking rental house. No opening a window doesn't count, just go outside (this was post smoking ban too so not an unusual requirement). Even when we smoked we never smoked in the house.
One kid (who wasn't even invited, just showed up as a tag-a-long of the invited kid) smeared chocolate all over the walls, ran from room to room uncontrollably and broke toys.
When I was a kid a visiting school friend stole my brand new just released 'must have' toy I got for my birthday, took it to school the next day claiming it was hers but didn't know my parents had marked it with my name.
The one that drives me mad though is when people snoop though, especially when they snoop then have the brass balls to criticize, 'Oh you just happened to look in our bedroom at the other side of the house on your way to the bathroom did you? oh and your appalled the chair has a pile of clothes on are you? I should organize the way you do should I? get to fuck and don't come back'.
All of these are reasons we don't host guests, we will meet you somewhere neutral like the pub.