Great Top 10 keyword research tools list. Thank you for posting Robbie! I really appreciated the feedback from the experts. There are a definitely a few tools here worthy of taking note of. I have also been using DYNO Mapper (http://www.dynomapper.com) as a keyword research tool. DYNO Mapper is a visual sitemap generator that delivers keywords on all pages of any site. The user simply inputs any existing URL into the system and it will scan thousands of pages.
In addition, you can dig into the paid side of search and find out what keywords your competitors are bidding on, and then leverage those keywords for your own organic benefit if you're not already doing so. Search Metrics does this as well, but I've found SEMRush to provide a greater range of keywords and they save more historical keyword data than Search Metrics.
Tip: Instead of targeting large keywords (with lots of monthly searches) in one main article – try targeting lots of long tail keywords in lots of different articles. I’ve been having success with this strategy for a long time now – and more recently Spencer and his team at Niche Pursuits have been using this strategy and talking extensively about it.