Note: This plugin is for b2evolution 1.6-alpha. I'll rerelease it once the beta is out.
The Most Comments plugin adds a box to the sidebar which displays links to the posts with most comments. You can use the params array to set the number of posts to list (along with whether you want to use an ordered list (default) or unordered and some other settings).
Installation is easy.
1. Download the file below, remove the .txt from the filename, then upload it to your plugins folder.
2. Add this code into your skin where you want the box to appear.
// MostComments plugin:
$Plugins->call_by_code( 'mostCmts', array(
// Add parameters in the array.
That's it. As always, feedback is welcome.