i know this is kind of an old thread, but i just joined and wanted to comment.
hi!
i could not answer the poll, actually, as i do like certain aspects of all three categories, and dislike others. my favorite scifi books deal with utopia/dystopia, and can often fall into the fantasy category. i think the reverse may also be true. i like fantasy that has time travel or metaphysical aspects which might also be deemed science fiction. i'm not into books about unicorns or people named ZXetds∫3q, though. it's really just that i don't understand them at all.
i do enjoy what someone here termed "hard" scifi, which we always just referred to as technical or technology-based. but i'm finding it more difficult to enjoy the older ones, as their arcane understanding of a possible future tends to be more off-putting than kitschy. and their attitudes toward women were often a bit silly. i don't feel that way about older dystopia examples as much, and enjoy the old stories that relied more on idea and character than possible technical advances or calamities that have not come to pass. and i love the irony-themed stories of the post ww2 authors.
as to horror, gosh, it seems like a whole other country, to me. but i like much of that as well, if it's smart.