This anthology is touted as an excellent introduction to SF. In its time (the early eighties), it would have been just that, being comprised of a rich cross-section of authors, and stories that touch upon most sub-genres (though one or two are closer to Fantasy than they are SF). Today, however, quite a number of tales have dated and might even put any potential new SF reader off. Space Odyssey is therefore much better read as a nostalgic trip down memory lane for the aficionado of today.
Stand-outs for me are: The Engine at Heartspring's Centre, Roger Zelazny (a melancholy tale of love in a euthanasia centre); The Tunnel Under the World, Frederik Pohl (the world is false, your life is false, only the adverts are true); '- And He Built a Crooked House -', Robert A Heinlein (four-dimensional real estate); The Third Expedition, Ray Bradbury (a haunting Martian Chronicles tale that always seemed a little out of place in that collection, but on its own seems to work much better); The Insect Tapes, Michael Scott Rohan (an amusing warning against fiddling with nature in a closed environment); Descending, Thomas M Disch (more surreal Horror than SF, but a strong reminder to read more Disch); and The Electric Ant, Philip K Dick (experiments with the perceived reality of an android).