I use market samurai,but I paid for it(didn't know it was free). As a matter of fact I used a coupon with a free trail,but when the trial was over I had to pay full price. That aside, I think it is a detailed analysis software with good videos to help with the learning curve. The problem I still haven't the time to absorb everything. Bottom line it does a good job, I'm just always in a rush when I use it.
When using keywords I had the sad experience of experimenting on what I thought were good keywords based on what I thought were good stuff from studying my content. I didn't think it was important to use keyword tools. Now I do.
I've had lots of success using Cyberzilla's keyword service on BHW. I'm also contemplating purchasing Niche Finder.
Market samurai combined with google keyword tool works great for me! Also technically the keyword section of market samurai is free... Which is awesome!
I use Google KWT, Market Samurai and Traffic Travis. Basically to check results against each other. Traffic Travis have just released their new version 4 as a free tool. (Sorry, insufficient posts to be able to isnert a link. Just Google Traffic Travis and you'll get there.)
The Google Keyword tool is very usefull. It's free, which is the best part. Otherwise you can use a program like Market Samurai.
Google adword keyword tool is best. you can use google trend, and google auto suggest keyword in serp.
I prefer to use Google Adwords keyword tool. It's free and one of best tool. It shows the most relevant searches.