Best comments plugin for large # of comments?

I’m going to be importing comments from a CSV file for some posts that were previously Joomla articles. One of these articles had over 1200 comments. Is there a specific comments plugin you would recommend for handling a large number of comments? i.e. good pagination feature, comments get indexed with search engine? I’m also interested in just everyone’s general opinion as to what the best commenting plugin is, if not the core one.