I think Google itself a Keyword tool. When we want to search with our main product keyword, Google show the most searching keywords with the word phrases. From them we can select the keywords for our sites.
Every seo experts use different keyword research tools. Keywords research is an essential part of the SEO strategy. For Keywords research you can visit Google Adwords, Word tracker.
Google keyword tools is the best and none can beat that but even the trail version of the semrush is also helpful which i mentioned in other thread recently ! no idea about the recently made tools !
adwords Google keywords tool is best and free as well.Don't look on others...It will be the best...just stick with it
Google keywords tool is fine....if you know how to use it to your advantage. Like has already been said, many paid for tools actually draw on Google for their data. Market Samurai for example does...although Market samurai does a lot more. Its competitor site analysis is really useful for example.
Google Adwords does a really good job if you know how to get the best use out of it. Don't forget to make use of the filters as these are really helpful when narrowing down your search. I especially love the new Ad Groups Ideas (Beta) that Google is testing. Hope it goes live