I first used the Free WP-Plugin SEO All in One plugin which is good if you have nothing but now I use SEOpressor because you can see your keyword density and relevance. It is a great but there are 2 other good ones which is a little cheaper. 1-Click WP SEO Wordpress Plugin and Easy WP SEO

Hey nice thread
I use yoast , so it gives me all I want. Im pretty happy with it

Check it out

There are a handful I use really:
Platinum SEO
Digg Digg
SEO Friendly Images
SEO Smart Links
PC Robots.txt
Google XML Sitemaps

just to name a few - and those are all free too!

I use Bloggerhigh SEO plug-in Free equivalent of Seopressor!

It's free and it's just lke SEO Pressor.

I use seopressor

All in one SEO till death, why change a good thing!

All in one SEO, prettylink as well

I find it easier to have SEO plug-ins created for me than to siphoned through and try to find the right options in the different ones already out there in the market.

We're using a custom plug-in that rearranges our links and titles as well as distributes duplicated converted PDF files to document sharing sites automatically.

One of our best programmers that we found was through a outsourcing platform like odesk

I use Platinum SEO and Clickbump SEO. Both great tools, easy to use - but there's a lot more that goes into ranking in the big G for me to comment on whether those tools on their own have increased rankings.

Indirectly helping me with my seo efforts, I use my wp-seoagency plugin to track all of my keyword rankings for all of my sites. One plugin install to track 100's of sites

Wordpress SEO by Yoast, brilliant.

All in one SEO - very good plugin for Wordpress.

All In One along with Easy WP SEO.

Google XML sitemap and All in one SEO.

S2member for membership and sales funnel.

I've been using Yoast's plugin and have been quite happy.

Go For Yoast Buddy!
This Would Really Help You !!

I use All in One SEO plugin in my all word press blogs.