Top 10 SEO Tools for Keyword Research:
Google Adwords Tool :
I thinks every one know about Google Adwords Tools, So nothing need tall about Google Adwords Tool.It is very likeable tool of every webmaster
http://www.adwords.google.com

SEM Rush :
After Google Adwords Tool i suggest SEM Rush because it suggest Keyword related search.
http://www.semrush.com

Spyfu :
Spyfu is another important Keyword Research Tools .by this tool you can keyword search in two ways.It help to search High Rank Keyword beside it suggest all information about the website.
http://www.spyfu.com/try-it-free.aspx

Woorank Website Review Tool:
Woorank Website Review is awesome tools by this tool you can see your competitor Keywords, Backlink, all information.
http://www.woorank.com

Keyword Spy:
Keyword Spy search keyword Word beside Suggest your selected Keyword competitor.
http://www.keywordspy.com/

Keyword Discovery:
Keyword Discovery searches your keyword and suggests 100 keyword from 100 search engine.
http://www.keyworddiscovery.com/search.html

Google Trends:
Google Trends is another Handy tool. By this Google Trends Tools you can see your Keyword description by Daily, weekly, Monthly.
Official Links of Google Trends:
http://www.google.com/trends

Word Stream Keyword Tool:
Word Stream Keyword Tool gives data about your searches Keyword, Such as Search volume, frequency and suggest competitor.
http://www.wordstream.com/keywords

SEO Quake:
SEO Quake is the tools of Mozilla Firefox.SEO Quake help to search Keyword, Birth date of competitor site, Pagerank, Backlinks & many more information...
Download link: