If you have any free ones to share please do it below. I'm interested in the ones searching free domain names after dictionary words. Thank you.
Hi - this is my site, but, I think the tools are really good, and are exactly what you're asking about. Keyword search for available domain names - for the free version, every search returns 50 keywords, and checks COM, NET, and ORG availability: http://genericdomainfinder.com/ There are also lots of lists of expiring or dropped domain names. Start here: http://www.genericdomainfinder.com/godaddyauctions http://www.genericdomainfinder.com/droppeddomains These lists are different from other lists of domains, because they only include real keyword domains, so you don't have to waste your time looking through 1000s of garbage domains like 000XKASSTUFF.com The appraised values are based on things like search volume, commercial value of the keywords, lenght of the domain, number of words, etc.
You could also try some web 2.0 domains generators - e.g.: http://www.dotomator.com/web20.html , http://www.webscriptlab.com/domainnamegenerator.php or http://suggest.name/ Good luck on finding some good names!