I personally use and highly recommend the following software's
This is specialized software for generating keywords for your SEO and Pay per Click (PPC) campaigns. You can even spy on your competitors to find out what they are doing (and it's legal).
Read Keyword Elite Review : Buy Keyword Elite now
This software by Brad Callen is similar to WebCEO and a great choice for search engine optimization. SEO Elite is a hugely popular software for search engine optimization and many experts use this tool. It's very powerful but still easy to use for the beginner. It contains functionality for everything you need in search engine optimization.
SEO Elite comes with a 50+ page SEO guide written by the SEO expert Aaron Wall, from seobook.com. Aaron Wall is the author of the best SEO Book in the market.
Check out SEO Elite
The king of Keyword research tools and endorsed by most experts. Known to have the cleanest databasewith statistics of search behavior of all keyword research tools.
I personally use WebCEO for most of my SEO tasks and are very satisfied but keyword research is so important that i want the best and also use WordTracker.
Take advantage of the free WordTracker trial
A great software for keyword research and highly recommended. The database is bigger and they have a few more features compared to WordTracker. The WordTracker database is however more accurate.
I frequently use Keyword Discovery for keyword research.
Check out the free Keyword Discovery trial offer
WebCEO - A fully integrated approach to SEO
WebCEO contains functionality to perform all tasks you need in SEO and it's really easy to use. Many activities in SEO is time consuming but with WebCEO is the result only a few mouse clicks away. I have saved countless hours and money after i started using WebCEO.
They have a free download containing most of the functionality with no obligations. They will in fact give you free support even if you havent bought the software yet. This is what i call service!
Download a free copy of WebCEO