Popular Tools Used by Webmasters

I'm just wondering what tools (paid for or free) successful webmasters use to monitor their competitors, the keywords on pages, etc.
I will try update this list as soon as I get some replies, as people might find it useful.

Here are 3 I know about:

Overture - Keyword Selector Tool

IBP & Arelis - Free(limited use)

WEB CEO - Free(limited use)

Average Pagerank of the top 30 pages of a site.

Google search classificated by Pagerank & by date.

Cheat checkers detect 4 kind of diferent cheat at the same time (PageRank, Redirection, Http header, domain)

Tool to Detect Pagerank and google Backlink Update in 400 DC

Quality rank (Human notation of website given by the webmasters)

Backlink Checker

Thanks to nifrou and geneuine

 

(mines )

- Average Pagerank of the top 30 pages of a site.

- Google search classificated by Pagerank & by date.

- Cheat checkers detect 4 kind of diferent cheat at the same time (PageRank, Redirection, Http header, domain)

- Tool to Detect Pagerank and google Backlink Update in 400 DC

- Quality rank (Human notation of website given by the webmasters)

 

Checking the backlinks is also very helpful, http://www.iwebtool.com/backlink_checker

 

Total Backlinks: 0
shit happens

 

Directory Submission Tracker
Backlink builder
Keyword playground
Redirect check
Quantcast - open internet ratings service.
Webmastereyes - see the Page Rank of all links in a page
Google trends - see what the world is searching for

 

I usually use Web CEO to get all the information I need.

And of course Yahoo's and Google's operators like site:www.yourdomain.com, allinurl:www.yourdomain.com, etc. just to get quick idea of how everything goes or to give fast advice.

 

does any1 have list of seo tools script to install on websites (brandable)