Apologies if this has already been suggested.
Some sites have functionality where posters can mark a post as a question, and then click a button to mark someone's post as "helpful" if it pointed them in the right direction, or as an answer, if it answered their question. Points are awarded, with some points given for "helpful" posts, and even more given for posts marked as the "answer" to a question. Users, after reading the original post, can click a link to go to the answer. (Or the answer would be in some other way made obvious.)
This gives credit to those on our site who have helped others, and, unlike a simple upvote/downvote system, can't be gamed (as easily) since the functionality would be available only to the OP of a question.
It also makes answers easier to find.
Just my two cents on what could make a great site even better!