Often, when people talk about aliens in science fiction, they trot out the old classics, Rendevous with Rama, The Gods Themselves, Stranger in a Strange Land, War of the Worlds, Ringworld, Childhood’s End, Starship Troopers. But these books are older than many of the people talking about them.
People didn’t stop writing books with aliens in them. Aliens are still out there. And there are some great ones.