You may not have heard of SERPAnalytics, it is a keyword tool and it is working fantastic for me, I have been using it fro last 6 months.

The main features are:

Competitor Research


* SE positions
* Traffic & traffic cost
* Ad keywords & texts
* Subdomains

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.

Position Tracking


* Sites monitor
* Keywords monitor
* Position dynamics
* Daily email reports

Track sites positions in Google. View position dynamics graphs. Use suggestion tool to track most profitable keywords for the site.

Keyword Research


* Paid competitors
* Organic competitors
* Searches & CPC
* Related keywords

Analyse keyword profitability. Find related keywords to expand your research area. Get essential information about sites competing in paid and organic searches.

SERP Tools


* SEO & SEM params
* Position dynamics
* Archived SERP
* SERP stats

Analyse SEO & SEM techniques using a comprehensive set of tools. Find out position dynamics for each site in the SERP. View archived SERPs to see changes in detail.