Well, since he doesn't have a spot on this list, I'm going to say Rory Williams.
Admittedly, when I first saw Rory I thought he was going to be Mickey Smith all over again - the slightly useless, ineffectual and moronic boyfriend of the Doctor's companion (before anyone jumps down my throat - yes, Mickey got better!) But when the Doctor - in his infinite wisdom - goes to pick up Rory so he can go with Amy on a little Time-and-Space themed date in "The Vampires of Venice," we finally got to see the guy that Amy's engaged to. And he is not the dweeby little twerp we've sort of been led to believe he is. He is completely committed to Amy in the sweetest possible way (taking on a dangerous alien space fish with a broomstick? WHO DOES THAT?) Sure, he's a little awkward and unsure of himself but I think something that happens when you travel with the Doctor is that you find the very best of yourself (well, most people do). And Rory's very best is the someone who wants to do what's right, be the most amazing guy for Amy Pond and maybe learn some basic TARDIS repair in the process (if he can keep his eyes off his wife's skirt long enough, that is).
(And Rory would definitely be the kind of guy a girl would want to bring home to her parents ^_^)