I've purchased and installed a new Post Rating system. This greatly extends the current "Like" system, where you can actually rate posts, rather than just liking them.
I'm taking the animated screen captures from the add-on thread on XF

Ratings list becomes more concise by hiding removing the rating names when a large variety of ratings have been applied to a post:

If a post does not already have ratings no solid bar is displayed until it has been rated, to further promote a clean interface:

Both forward and backwards compatible with XenForo's built in likes - legacy posts will have Like ratings displayed (by default) and new Like ratings are passed back to XenForo to handle as actual likes (again by default):

'List' links to overlay displaying who has rated the post:

This list can easily scale to large numbers of ratings on a single post without breaking the clean design:

Users with the appropriate permission can delete any user's rating from the rating list view: (The X button is displayed on hover of each section to reduce clutter)

Members interface:
Member card integration showing total positive/neutral/negative ratings received by the user:

Profile page integration listing the total number of each type of rating both given and received, as well as total positive/neutral/negative received:

Members list integration:

Online list integration:

Visitor panel integration:

Replacement for Likes You've Received page:

As well as extra Ratings You've Given page:

Alerts/News Feed/Recent Activity:
Fully integrated with the XenForo Alert system:

Fully integrated with the XenForo News Feed system, which powers Recent Activity both globally and the tab on user pages, and also to users' private News Feeds:
