Well, there is no doubt about it as lots of keyword tools are exists but there is one fact is all of them may not give you accurate result which is actually real.
One of them is Google Adwords keyword tool, it is free thats why it is too popular but in really it is also not so useful in term of accuracy, you may clarify this doubt with any experienced SEO as well.
The question is which keyword should we use for better result?
We should be a little smart if we are doing SEO or internet marketing, if we are required to pay a little for any keyword tool then we should pay, if we pay a little then we can get a lot, believe me it is a fact of internet marketing...
What I would recommend is SerpAnalytics, it is all about keywords, competition and SERP, it is working good for me.
But you have to learn it first about how to use this tool, once you learned everything would get much easier for you....
What is SERPAnalytics
SERPAnalytics is a first online SEO environment designed for SEO & SEM specialists.
SERPAnalytics provides a variety of SEO tools along with access to millions of records of essential data including search engine positions archive and keywords data.
Some main features..............
* SE positions
* Traffic & traffic cost
* Ad keywords & texts
Discover competitors in paid and organic searches. Know more about site's ads: texts, keywords, costs, positions. Learn about top traffic and top paying keywords for the site.