Hmm. I can recommend a number of them. A lot of the books I have been reading lately have been part of a genre known as isekai. That's basically Japanese for 'another world'. The genre isn't unique to Japan, or we wouldn't have the likes of the John Carter or Narnia books, but it's one of the most popular genres in Japan.
That being said, isekai is very much an illustration of Sturgeon's Law, which is basically 90% of everything is crap. The only three isekai series that I would recommend to newcomers to the genre would be Overlord (not to be confused with the Rihanna Pratchett-penned video game series), Rising of the Shield Hero, and The Saga of Tanya the Evil. Those three are still pretty dark, though. The first one basically has the main character gradually becoming a villain, the second starts with the main character being framed for rape, and the third one...well, he's a sociopathic HR manager reincarnated as a child soldier in an AU of World War I by a petulant deity...and a girl.
That being said, isekai is very much an illustration of Sturgeon's Law, which is basically 90% of everything is crap. The only three isekai series that I would recommend to newcomers to the genre would be Overlord (not to be confused with the Rihanna Pratchett-penned video game series), Rising of the Shield Hero, and The Saga of Tanya the Evil. Those three are still pretty dark, though. The first one basically has the main character gradually becoming a villain, the second starts with the main character being framed for rape, and the third one...well, he's a sociopathic HR manager reincarnated as a child soldier in an AU of World War I by a petulant deity...and a girl.