It would appear that Reddit uses the Wilson score interval to calculate the 'best' comment in the stack.
An explanation can be found here: http://amix.dk/blog/post/19588
However, this only seems to apply if you have a binary rating system (e.g. upvotes/downvotes). If instead, you have a singular rating system (like Facebook "Likes"), this method won't work as p = n ( p being the # of positive votes, n being the # of votes).
One method I can imagine that may work is set n to be the # of votes total in the system, or the # of votes on the maximally rated item.
Is this approach flawed?