Looking for a book recommendation with a long premise I can loose myself in and with great-interesting characters and a decently written plot

Hi there people, first time posting here. As the title explained I am looking for a book or book series that I can loose myself in. I am looking for something in fantasy or science fiction genre. For example I loved Dune books and read 100 page in a daily basis until I finished them, so you can say I am looking for something like Dune(great characters, interesting concepts, in-depth lore, a long story etc.)

I also normally prefer to read classic books like Dostoyevski and Tolstoy are my favorite writers with Crime and Punishment being my all time favorite book, but I also enjoyed newer and more popular titles like GoT, Witcher, LOTR and Harry Potter books too.

I am open to any suggestion you may have and thank you for the help!