May be this link can help you http://www.seoworkers.com/tools/report.html youcan take a look at your keywords on your site, its density and a complete report on it

I have used a few of those free tools and recommend them to people starting out!
But I can't help thinking we are all pro's to a certain degree and the bottom line is "It's hard to beat a good paid tool" for results and time saving?

I completely agree on Google AdWords Keyword Tool, it's excellent. I always use it for finding quality keywords. But to achieve success you need to do a lot more than just using it.

There are lots of SEO tools on the market, shop around and make sure that you get the right one. If SEO is just a personal thing for you and you're just trying to SEO your own personal site for example, cheaper free tools are fine.

If you're doing it corporately and need to deal with lots of clients you're best investing in a more in-depth solution, whereby you can produce client reports and configure different modules to provide a more attention-to-detail type of SEO work, as this is essential when doing this sort of work in order to be accurate.