Google Keyword Tool – This tool is FREE to use and is probably the most commonly used tool out there for obvious reasons. It is best to create a Google account so that you don’t have to keep typing the “Captcha” words every time you use the tool. Just a side note, it’s best to use the “exact” words/phrase by clicking the little box next to the word “Exact” in the left side of your screen. This way you can see more precisely what kind of competition your keyword/phrase really has and how much traffic it is drawing each month according to Google.
Market Samurai – This is a tool that is more commonly known for it’s detailed keyword research, but you can also use it to analyze your SEO competition, help with deciding on a keyword targeted domain name, and to build high authority backlinks to name a few things. Probably the most popular paid tool out there. It’s a one time fee for the tool that you can start with a free trial. (Hint: If you’ve previously tried the trial version of Market Samurai, you can still get the promotional price of $97 by using a different email addy. That way you don’t have to pay the normal $149. Thought I’d help you save a few bucks there. )
(This page is a work in progress. More to come)