Opinions Please: Best Optimization Plugins for WordPress

I am researching plugins for WordPress. Any opinions you may have would be greatly appreciated.

What are your thoughts on the following Optimization plugins for improving SEO & Keyword Testing:
* All in One SEO Pack (plugin for SEO)
* Yoast SEO (plugin for SEO and keyword testing)
* Google Keyword Tool (not plugin, but easy to find testing tool)
* HubSpot (paid keyword testing tool)
* SEO Raven (paid keyword testing tool)

What experience have you had with these? Reliability? Ease of use and maintenance? Security concerns? Effectiveness?

Are there others you would recommend instead?

Many thanks!