Sands of Mars is a bit too naive, so it's a bit hard to get into. I found Childhood's End very spotty. Rama is very good. City and the Stars is one of his best. 2001 is one of the great SF novels, regardless of the film. But I think some of his collections really show his talent. The Sentinel is my personal fave. I've started Fountains of Paradise so I'll let you know what I think. (As if I wouldn't.
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