1. WordPress SEO by Yoast. It is one of the most downloaded WordPress plugins of all times.
2. SEMrush.
3. Google Keyword Planner.
4. KeywordTool.io.
5. Open Site Explorer.
6. LinkPatrol.
7. Broken Link Checker.
8. Rel NoFollow Checkbox.
Contact Form 7. ...
Yoast SEO. ...
Akismet Anti-Spam. ...
WooCommerce. ...
TinyMCE Advanced. ...
WordFence Security. ...
Google XML Sitemaps. ...
WP Super Cache.
I am using all these wordpress plugins for one of my Wordpress website.
I have done SEOs on hundreds of websites and from my experience, I am posting some of the great Wordpress SEO plugins. Here is the list:
Yoast SEO
All in One SEO Pack
The SEO Framework
SEOPress
Rank Math
SEO Squirrly
Broken Link Checker
Rel NoFollow Checkbox
All in One Schema Rich Snippets
WordLift
Depends on the amount of knowledge you have on search engine optimisation for websites. If you know nothing i would go with the yoast plugin. I wouldn't however rely on it to get you great rankings and many features that we used to custom code into websites are premium features of yoast, so get yoast but with buy premium or learn a bit about coding and seo outside of plugins.