when I do my keyword research I use google adwords and look for exact volume. I personally go for keywords with 5,000 or less exact competition.I also use the yahoo site explorer tool to check out the competition for my keyword phrase. Hope this helps.
Google keyword tool would be my top choice. But as an alternative, I sometimes use Wordtracker when Google keyword tool is acting nuts.
You know the world's biggest keyword tracker is on this site, right? http://tools.digitalpoint.com/tracker.php In fact, this forum is the support forum for it.
I thought this tool was discontinued because google stopped something that made it work? Or am I thinking of a different tool?
Please disregard my last I am using it now, what a good tool. I think I was thinking about adwords keyword spy or something similar.
Google Keyword tool is best where you set any google adword campaign... Because that two tools is from google so... But word-tracker is also good