I think quite a few of us now use GoogleAlerts as a basic form of reputation management/or to help us keep up with the conversation around the web.

These would be my top picks and by the way, only one isn't free.

rexswain.com/httpview.html
tools.seobook.com/firefox/seo-for-firefox.html
ibusinesspromoter.com
xml-sitemaps.com/

Thanks for the nice collection. I think the problem is finding tools that are accurate and up to date.

Why is SEO Book for Firefox not there? Common guys, anyone knows of a better seo tool? Also Link Diagnosis tool is great (www.linkdiagnosis.com)

Great information! This is something any SEO could use!

Do not forget SEO Quake FireFox Add-on.

https://addons.mozilla.org/en-US/firefox/search?q=SEO+Quake&status=4

It adds a toolbar that displays page rank, google/yahoo index and links, Alexa Rank, Age, IP, Who Is data, Last Cache Date, # of Internal and External links, Page density and number of pages in the supplemental index.

I'd go with Hitwise products and Search Intelligence. I'd agree with Clicktracks all the way. The Search Status toolbar by quirk.biz for Firefox is what I use too.

Advanced Web Ranking
Advanced Link Manager
http://www.caphyon.com/

I seriously couldn't imaging doing my job without either of those. They have saved me lifetimes of grunt work.

This is a nice little list. I think we all have tried as many products as we can get our hands on, but I have to agree with a lot of this list.

Thanks for the info ,will try them out and let you know .

Thanks for the list! I find the Search Status for Firefox Toolbar very useful.
available here: http://www.quirk.biz/searchstatus/

Under Keyword Tools, I would like to add these two:

https://adwords.google.com/select/KeywordToolExternal
https://adwords.google.com/select/TrafficEstimatorSandbox

Firebug plugin for firefox is a good way to see both the html and css of a web site while browsing the net

I use this link ranking tool to check how many sites are linked back.

http://www.seocentro.com/tools/search-engines/link-popularity.html

You forgot content linking tools like Arkayne. Its a widget that links your blog with relevant sites. Not a traffic exchange just a relevance engine.

For the curious: http://www.arkayne.com

I enjoy SEO Digger for analyzing your competitor's keywords/keyphrases rankings.

http://www.seodigger.com/

Thanks everyone for the great suggestions. This is great, useful info.

Great resources. This list definitely hits the major tools for SEO. Coupled with good content and the right strategies on the site, they can be a success. Just keep in mind SEO isn't the whole game - an easy fact to forget anymore.

Been seeing some good tips for internet marketing on http://www.massmailsoftware.com/blog/ - once they get to your site, sell!

Hi,

Great and useful article on tools. Here is another link with valuable webmaster free tools.

http://www.seoservicesgroup.com/seo-tools/seo-tools.html

Hi,

Just wondering what you're thoughts are on ibusinesspromoter.com?
thanks.

I can nearly bet that the most answer will be that seo-guru uses no software and do everything by hands ))
Absolute best 2 tools out there are:
1) The Human Brain
2) Experience
The Best tool for SEO comes not in a software, it is not promoted in any website, it's not available on Google and you cannot access it on any forum. The best tool for SEO is the SEO person itself. No matter which SEO tool you would be using, it is still the person who will decide on which will be the best approach for the site. It is still the person who makes a site successful or the one who makes it crash..