@Last Mitch.. Majority speaks Google ad word as the best...i don knw any other free keyword tool none other than Google..i have used google ad words many times which is still now to be the best. i wanna know many other keyword tool,so i created this discussion
Google adwords Keyword tool is Google’s official AdWords keyword research tool. The tool generates keyword ideas and analytical information on each term. Also give the information about compitition of Keyword. This is best tool for Keyword research.