Sure. 'That Time I Got Reincarnated as a Slime' is a completed isekai novel. In this story, a man is reincarnated as a slime in a different world and gradually builds his own powerful nation. 'Konosuba: God's Blessing on this Wonderful World!' is also a completed one. It has a comical take on the isekai genre, with a group of misfits going on adventures. Additionally, 'Grimgar of Fantasy and Ash' is a completed isekai that focuses on the characters' growth and survival in a harsh new world.
One popular completed isekai novel is 'Sword Art Online'. It combines elements of virtual reality and isekai, where the main character is trapped in a virtual world. Another is 'Re:Zero − Starting Life in Another World'. It has a unique plot where the protagonist has the ability to return by death, making for a very engaging story. And 'Overlord' is also great. It tells the story of a powerful being who gets transported to a new world and his adventures there.