Sometimes there are multiple responses to a forum thread with suggestions to fix a problem. Often only one of the responses really helps the originator. To help readers that run across the thread later, the originator can mark a specific response as the most useful or the preferred answer.
This request is to develop a way for the originator to mark a response as useful or the preferred answer. Only the originator would have this ability.
Once a response is marked as the preferred answer, consider displaying that response with different visual styling such as a different background color or an image. Also consider repeating that response directly below the original post.
Extra credit: Include the ability to assign points to responses that are marked as preferred. The person who created the response can earn these points over time and be flagged as a subject matter expert (SME) and being recognized with an SME badge.