I will nominate @surgo for his funny horrible experience :

I have keys but no locks. I have a space but no room. You can enter, but can’t go outside. What am I?
Keyboard. Quite obvious.
What flies when it’s born, lies when it’s alive, and runs when it’s dead?
I was at a loss for a while, and eventually made the connection with states of matter. My best guess, at a massive stretch: snow. However, it doesn't feel right, as we're talking about things which are "alive".
I was looking into bugs, like a caterpillar/ butterfly/ whatever (I'm not an entomologist), but couldn't find anything that would fit.
So I Googled it, and it's supposed to be a snowflake. WHY. Terrible riddle. 0/10. Wouldn't consider it again.
What comes once in a minute, twice in a moment, but never in a thousand years?
M.
I spent far too much time trying to figure it out, until I tried focusing on the spelling, at a complete loss.
Quote marks exist for a reason. 0/10, wouldn't repeat. Horrible experience.
A worker is placing the windows on the 50th floor of a skyscraper, suddenly, he slips and falls. Is he alive or dead?
He's alive. Installing windows generally happens from the inside.
Alternatively: he couldn't slip if he was outside the building on one of their lift things - they have anti-slip surfacing generally. Also safety equipment.
A woman is sitting in her hotel room when there is a knock at the door. She opened the door to see a man whom she had never seen before. He said "oh I'm sorry, I have made a mistake, I thought this was my room." He then went down the corridor and in the elevator. The woman went back into her room and phoned security. What made the woman so suspicious of the man?
Lots of answers.
He was naked (say... on drugs?)
He was injured (in shock, thus the good manners)
He had a gun (went out to get it to kill himself)
He knocked on the door of his room (although he might as well have been knocking to check if his traveling coworker is decent).
etc. etc. etc.
Riddles aren't my sport, but I do find the vast majority of them far too vague to be of any use.