Fantasy Science

What is the best in-print anthology of science fiction/fantasy short stories, suitable for a college course?

I am redesigning a speculative fiction course (science fiction, fantasy and horror) and would love suggestions on in-print anthologies I could use. I have several on hand, but I’d like to make sure I haven’t missed one. It would also be helpful if it is printed in the U.S.
Gardner Dozois’ anthologies are excellent, but they only include current stories, not classics. I do need an anthology that includes a good representation of the three respective genres’ “best” stories, such as the work of Asimov, Heinlein, LeGuin, Poe, Lovecraft, etc. Thanks everyone for the great input so far, but I’m still looking.

I really cannot remember which one I used. I could look in my library and if you write to me I could let you know. One thing – if should have the story 2017 or Thereabouts in it. That is an amazing story. As I recall the book I used had a silver cover. It may have been the Norton One – but since that ends with 1990, you may want something more updated. Still, try not to miss that story. It is incredible. Pax – C

Terry Pratchett: Science Fiction or Fantasy? – Mark Lawson Talks ToTerry Pratchett – BBC