There was a story I have had in my head for nearly my whole life. Ever since I was like 3 I had a story idea that was basically an Isekai. A guy who on his sleep is in a fantasy world with knights, magic, and dragons; while he sleeps in the fantasy world he is in the "real world." I put real world I quotes because the real world was basically a sci-fi world like our own but the main difference was everyone had a chip Implant that served as a TV, computer, and telephone in one where you can have an imaginary screen pop up in front of you and play Mario or metroid or something. Well basically the real world was like Accel world and the fantasy world was like any other fantasy world.
Edit: I have added way more over the years.