Here are some of the best and most installed WordPress plugins in 2024, covering various functionalities essential for optimizing and managing a WordPress site:

1. Rank Math: This is a top SEO plugin offering comprehensive tools for on-page SEO, keyword optimization, and seamless integration with various WordPress builders.
2. WPForms: Known for its ease of use, WPForms is a powerful form builder with drag-and-drop capabilities, pre-made templates, and advanced features like payment integrations and spam protection.
3. Yoast SEO: Another leading SEO plugin that helps with keyword management, readability analysis, and automatic XML sitemap generation.
4. Elementor: A popular page builder that provides a visual design interface, making it easy to create custom layouts and designs without coding.
5. MonsterInsights: This plugin integrates Google Analytics with WordPress, offering insights directly from the dashboard. It is especially useful for tracking visitor behavior and optimizing for conversions.
6. WooCommerce: Essential for any eCommerce site on WordPress, WooCommerce offers extensive features for online store management, including product listings, payment gateways, and inventory control.
7. UpdraftPlus: A reliable backup plugin that supports cloud storage solutions and offers one-click restoration and site migration features.
8. Wordfence Security: This security plugin includes a firewall, malware scanner, and tools for monitoring live traffic and blocking malicious attempts.
9. WP Rocket: A premium caching plugin designed to speed up website performance through caching, Gzip compression, and file optimization.
10. Contact Form 7: A flexible and straightforward form plugin that allows you to create and manage multiple forms, with support for AJAX-powered submissions.
11. All-in-One WP Migration: Facilitates easy migration of WordPress sites with a simple drag-and-drop interface, supporting various storage options.
12. Really Simple SSL: Automatically detects your settings and configures your website to run over HTTPS, ensuring a secure site.
13. LiteSpeed Cache: A caching plugin that enhances site performance through comprehensive cache management and optimization features.

These plugins are widely used and trusted by the WordPress community for their robust functionality, ease of use, and the ability to significantly enhance the performance and security of websites.