Keyword analysis ,keyword position and keyword difficulty check tools

Googling for the term "seo tools" returns several SERP but choosing the best is very important. Let me give you a few tools that i use :

For Keyword Analysis :

http://www.live-keyword-analysis.com/index.html

http://www.seochat.com/seo-tools/keyword-suggestions-google/

http://www.keyworddensity.com/search_engine_optimization/keyword_density.cgi

Know your keyword position in google SERP :

http://link.ezer.com/tools/google_serps_rank_checker.asp

http://www.seochat.com/?go=1&option=com_seotools&tool=30&go=1&imageverify=HEC3B&timehsh=484330695869733d&toolsubmit=Validate

Keyword difficulty check :

http://www.seochat.com/?go=1&option=com_seotools&tool=26&go=1&imageverify=8LGBQ&timehsh=6243516d4c7a673d&toolsubmit=Validate

The above tool is more interesting because its very difficult to get top positions in SERP for specific keywords and you may try to concentrate less on them .Instead go for "less difficult" keywords and see to it that they are somewhat preferred keywords by googlers if not the top ones .