Like Grandmaster Strategist. It has a good story. A good character. He is smart but not op. A good writing style. The language level is higher than other webnovels. (Ze tian had these points in common too, except the mc was kind of strong but limited by his lifespan) (The World Online was similar, very interesting) Maybe it should be Chinese. The best webnovels I have read were Chinese except pto and LMS
You could start with Dungeon Defense, as it is one of the recommendation I can go by from NU's recommendation you see under a novel title. Another one which I'm enjoying right now would be Isaac. It's really starting to kick off from the recent chapter as it enters a new volume. No more 'school holiday' for our MC. It's time to get his brain moving and running now that the world is trying to kill him.
Lord of the Mysteries Divine Throne of Primordial Blood Renegade Immortal I Shall Seal the Heavens Nightfall Reverend Insanity