I think my biggest fictional crush is The Boss from Metal Gear Solid 3. She's a strong-willed character, absolutely honorable to the death, and one of the best, well thought out characters I've ever seen. I don't think she falls under the category of absolutely beautiful, but she's realistically gorgeous. Everything about her is real, and there's nothing there that screams fake to me. Her hair isn't 'shimmeringly perfect,' her body is 'strong yet scarred,' and she has the facial markings of someone who has had real issues and really looks like she has gone through absolute hell.
On the male side of things, I'm absolutely in love with Vergil from Devil May Cry 3. (NOT DMC.) He's cocky, a huge jerk, completely out for himself, but he has his own reasons for doing things that I can admire. At the end there, he kind of turned his self-centered plight into something a bit more honorable. Though it's still not perfect, the guy is trying to take down the god of hell itself. If Dante can shed a tear or ten, so can I. Of course, there's the aesthetic appeal to him as well. He's not as real as the boss is, not by far, but he's also not some pretty-boy that doesn't look like he could get carried away by the wind either. He's built like someone of that size should be, and I find that very attractive.
EDIT: Same reasons as Vergil, Caius Ballad from FF13-2.