Google Keywords Tool is the best and It has been updated with various function so you can try this one for your healthy business.
Why not look at a keyword tool review site, this would provide you and understanding and insight of the best keyword tool to use. I searched over the internet and looked at different products .
Google's search volume data is arguably the most accurate one. There's hardly a service that knows what users search for on Google better than Google itself, the only question is how much of the data Google wants to share. You can take a look at wordstream tools, I think they are one of the few companies that don't rely on Google for search volume data. Other than that I'd suggest using automatic suggestions from different search engines, these are based on real world searches, so be sure that there's search volume behind those strings. Also dig up your own referral logs and webmaster tools impressions data, there are often real gems there.
According to my experience, Google Adwords keyword tool gives you search data more than actual. I use SerpAnalytics and KeywordDiscovery these two work good for me.
Well there are lots of key word you can go for Keyword tool,Samurai,Google Adwords and many more or you can also go go for Google search for new keywords.
Google adwords keywords tools is really good then all of others bcz in now days google on top and they dont want that any product of the google get loose ranking so they work hard on it its better then other.