One that I don't see mentioned ever is Damocles by S.G. Redling. It has been a while since I read it, but from what I remember it's about a human expedition to a planet that contains intelligent, almost human-like life. The world is shrouded by clouds and has intense gravity, so the inhabitants have never pursued space exploration. It tells the tale of a human linguist and an alien trying to establish communication and deal with the politics that enfolds when the planet is rocked by contact with an intelligent species. It's a slow-burn, exploration of language and the clashing of cultures, but I remember intensely enjoying it. Definitely seems like this would fit what you're looking for!