Isekai, the fantasy setting where (usually) modern people are transported to a fantasy world, a game world, or some strange setting (as well as the reverse). This kind of background has existed for at least 20 years but has become very popular in the last 5.
What are your favorite series? What are your most hated ones? Is time travel i.e. Zippang, Shut Hell, and Gunjou Senki isekai? Why is this a bad trend in anime/manga/novels? Was publishing people who failed the first time in getting their novel published because their story got popular online (where its free) a mistake? Is the setting necessarily bad or can it be done well?