It is seldom that there is one best answer to a SoPW - either the question has a fairly obvious answer and many replies of similar merit are posted at essentially the same time, or the question is explored in many different directions, often at great length, by several monks. In both cases it would often be wrong to single out "the one best answer", especially as doing so may mean that other worthy answers don't get posted.

It is worth remembering at this point that SoPW nodes server two purposes - to provide the product of others wisdom to help the seaker find a solution, and to share that wisdom with others who may have a similar problem. To that end damping down the enthusiasm for posting a variant answer by saying "don't bother trying, the best answer has been posted" is somewhat counter productive.

A better solution, as suggested above, is to tag the OP's node as having had a suitable reply. In principal at least a standard notation in the OP's node could cause a suitable class attribute to be added to the heading line HTML so that it is obvious which posts need attention, and which have an answer the OP deems suitable (but are worth reading for interest and enlightenment of course).