Lucifer’s Hammer - Larry Niven and Jerry Pournelle
Ringworld - Larry Niven
Rendezvous With Rama - Arthur C. Clarke
“Rendezvous With Rama”
That is one of my favorites, too. They keep threatening to make a movie of it. I am also a fan of “Childhood’s End”.
Read all three. I would like to see Ringworld and Rendezvous With Rama made into movies. I feel Lucifer’s Hammer has already been done, with the movies Armageddon and Deep Impact.