Item Rating is definitively the most powerful system to display product reviews and ratings in Joomla, K2 and multiple other Joomla extensions. The extension has the voting flexibility you've ever had before.
Demo: https://www.joomunited.com/products/item-rating
Stellar is a star rated plugin for WordPress. This plugin can create and save ratings for every WordPress post, be it a post, page or product.
Demo: https://codecanyon.net/item/stellar-star-rating-plugin-for-wordpress/25336975
Liker is a plugin for collecting WordPress post and page ratings. The plugin allows you to quickly and accurately collect information about the usefulness of your articles.
Demo: https://codecanyon.net/item/liker-wordpress-rating-plugin/24570827
Add detailed post reviews blocks with unlimited rated criterias, negatives and positives lists, summary, affiliate buy button and more to any of your WordPress blog posts and display automatic total rating on single post page and blog listing pages.
Demo: https://codecanyon.net/item/ultimate-post-review-responsive-wordpress-posts-reviews-and-rating-plugin/23841089
Yasr Premium is a powerful way to add SEO-focused user reviews and testimonials to your website posts, pages and CPTs without impacting their speed.
Demo: https://yetanotherstarsrating.com
Easy to use rating system for your WordPress site with a niche of doing multi-ratings better than anyone else.
Demo: https://multiratingpro.com