This one is rather obvious. The first couple listed is Harry and Ginny. Let's face it, they're so cute together. And Harry pulling a Spiderman "I can't be with you" isn't going to keep her away. If both of them live, this is for the long-term.
Ron and Hermione: Really? Is anyone not convinced about this? They are so opposite, yet so perfect. Maybe they can finaly, officially, get their act together in book 7.
Harry/Hermione: not a chance.
Lupin and Tonks: I adore this couple. I really hope they both live just so we can see them grow old together!