Ahrefs + LongTail Pro + BaclinkIndexer ...

I will suggest market samurai tool which is a more powerful tool in which you can track your competitors planning and how much backlinks they are gaining from different sources

1. google keyword planer
2. Longtail
3. Backlinkwatch.com

i use Market Samurai .

I use Bruce Clay SEO toolset along with Majestic. For positions, I use Serpbook - this is the best combination of tools you need. Bruce Clay gives you on page reports and compares your site on page seo to others. Check it out!

There are very much seo tool? You can use some tools
1. Ahref.com - Check Banklink, Anchor text, Dofollow...
2. GSA - Building link.
3. Google keyword planer and google trend - Keyword research

Blackhat seo is over. That where the days

1. Seo Quake
2. Mozbar
3. Ranksignals
4. Homechecksite.com

the incredibly useful tool and I use it regularly at work

I use :
1. Ahrefs.com
2. Backlinkwatch.com
3.Seoquake
4.Webmaster tool
5.Backlink indexer

There are many seo tools for many purpose like google webmaster, ahrefs, backlinkwatch.com, pagerank.net, moz.com, google adwords.

Ahrefs.com this site to check backlink

Tool :
Ahrefs.com
Backlinkwatch.com
Google Webmaster Tool
Spin Content
backlinkindexer
...

My favourite tools are Seo profiler, open link profiler, Google Adword tool these are some tools which I daily use

SEO onpage: keyword, site structure, plugin
SEo offpage: forums, blogs, social network... comment

Adword and Keywordtool.io
 

I always use Adword and keywordtool.io. for my health blog.:)

Use google key planner, i think its best