Rendezvous with Rama

This book was basically my introduction to SciFi novels. I am, as I always been, a fan of science fiction, Hard SF rather that Space Opera.
And this is -in my opinion- as Hard as it gets in SciFi. Nothing gets in the way of detailed exploration of an unknown alien world like Rama.
Characters are well drawn, by the end of the book you feel like a member of the main exploration team and you know major characters by heart.

The fact that there is no major plot twist is amazing, this means you can't get spoiled with this book, and consequently you can read it several times and still enjoy it!