I really enjoy the works of Orson Scott Card (though the Xenocide trilogy was a bit of a bore). Starship Troopers is a perpetual favorite. Stargate SG-1 and Firefly were fun, and Star Trek is almost always worth a watch (though Voyager was a little rough). One of the things I like about 40k is it is intentionally open. You can tell any story you want in it and it will obey the rules of the setting with a little tweaking. Star Wars is awesome for this reason too, but the current season of Clone Wars is burning me out.
I'm going to give a shout out to Fifth Element, because someone should.

I wish I could 'get' Doctor Who and Battlestar Galactica (they seem so neat and there's clearly a lot happening, it just doesn't click for me) and that I could ignore the random exposition dumps and awkward monologues that fill most of my memories of Babylon 5. It's not a bad show by any means, it had actors that made you overlook a lot of the 'cheap' and sold their characters so hard that it seems like a natural interaction (until the monologue or exposition dump knocks you out of it).