I don't much care about your hair/eye color, race, religion (though atheists are probably easiest), breast size, or how many solar orbits you've completed (as long as you've become approximately adult-like and don't seem old). What I do care about: you are adventurous, open minded, reliable, can hold up your end of an interesting conversation, know how to keep your own head above water when it comes to everyday life, enjoy some socially-discrete-but-privately-explicit kink in your love-life, your mental aberrations are relatively benign, and you are not a dyed-in-the-wool muggle or part of the Legion of Normals. It would be nice if you were a good travel companion. And I'm a sucker for a nice rear view.
Favorite authors: Ursula LeGuin, David Brin, Verner Vinge, Neal Stephenson, Isaac Asimov, Neil Gaimen, H.G. Wells, Jules Verne, ... etc. Currently reading 'Isaac Asimov's Guide to the Bible, Vols. I and II', which is really fascinating - even for an atheist.
Food: anything good. Particular to high-end pizza (not Domino's or Pizza Hut), Thai, Mexican, and sushi. Not so much into pickled toad or boiled sea cucumber.
Music: Shpongle, Lamb, Led Zeppelin, Hendrix, Bowie, Beethoven, Bach, Sneaker Pimps, Foo Fighters, Pixies, Ladytron, Gorillaz, Johnny Cash, Portishead, Neil Diamond, Marlene Dietrich, Amon Tobin, Joy Division, Radiohead, Black Sabbath, Kilowatts, Bowie, Chemical Brothers, Crystal Method, Vivladi, Beatles, Salmonella Dub, ... and much more. Very open to being exposed to your favorite music.
I don't/won't watch sports (exceptions: tennis and some Olympic events) or listen to contemporary country music (no exceptions to the latter).
A little more down to Earth: Where my keys have gotten off to.
...you want to know how some science thingy works.
...you are partial to the combination of adventurous AND reliable.
... if you are good at writing screenplays - I have a script in my head, and could use some help getting it on paper.
... you like sailing on catamarans (and can wait for a windy day)