I would never have guessed that Sagan, a hardheaded, agnostic, scientific type would have in him a book with such a fine sense of character development and emotional pitch. Having read many of his nonfiction books, I was not surprised by the social and religious commentary, which I found to be both perceptive and very even-handed.
The science was interesting -- particularly the mode of travel described -- and I found the use of messages buried in irrational numbers to be an imaginative concept that I've never seen before. As a sci-fi story, I would compare this favorably with some of Arthur C. Clarke's best work, including "2001" and "Rendezvous With Rama," in terms of the scope and majesty of the universe he creates.
My only problem with the story, in fact, is that it is a little bit too derivative of Clarke; the space/dimensional traveling sequence seems to be imitative of "2001," and there are other similarities to Clarke novels, such as "Childhood's End," that were a little distracting (that's why, on a scale of 1-10, Contact would get a 9, rather than the full 10 rating). Nonetheless, I found this a very moving story that has more genuine feeling in it than almost any S-F story I've read.
This is a novel that is visionary and almost religious in its awe of the universe -- the movie was also enjoyable, but as is almost always the case, it can't capture the numinous feeling that the book has, despite a great performance from Jodie Foster.
Don't let some of the religious nuts' reactions scare you away from this book -- it has more genuine spirituality in it than a whole room full of Baptists and 700 Club members.