If your site gets a lot of reddit posts this will help increase engagement (more upvotes/comments)
<script src='//redditjs.com/post.js'></script>
<script src='//redditjs.com/post.js' data-height='500' data-width='650' data-post-finder='mostComments' data-theme='dark' data-show-submit='true'></script>
I wanted this to be similar to a facebook comment widget, websites that get a lot of traffic from reddit would benefit greatly by getting more upvotes/comments on their content.
You can see live examples here.
I also created a subreddit feed widget similar to reddit.com: reddit widget. I feel the one I've created gives the user more options and a better user experience.
Both of these script tags can be autogenerated for you if you use the Reddit Embed Wordpress Plugin