Now they are all too young for me, but let's ignore age for the good of this question.
I'm a heterosexual guy, so the girls will have to do for me. And then I am thinking about one of the girls in the "Secondary Trio" (That's the Neville-Ginny-Luna trio).
I like Ginny for her I-don't-take-shit-from-anybody attitude, but in the same time she likes a good joke, is very loyal to her friends, and although she does not allow herself to be enslaved, she does a lot for you.
And Luna is a girl I can relate to. Although I do not believe in Nargles, and I must admit that at first I was not sure what to think about her, when you actually get to know her, you'll discover a sweet, loyal girl, who treats everybody (even Goblins and House-Elves, are are mostly held in low regard) equally, and she does not question strange behavior in others. She just wants to be your friend. And of course, Luna is brighter than you might initially think (although the Sorting Hat must have seen that, or it wouldn't place her into Ravenclaw) and when the going gets though, she does show the heart of a lion (making her also well fit to be a Gryffindor).
Of course, Harry attended Hogwarts in 1991, when he was 11, meaning he would today be 30. Hmmm, that must mean that Luna and Ginny are both 29 now (since they are both approx 1 year younger than Harry), Okay, maybe age isn't that much of a problem, anymore. π