Aside from the Google tools and the SEOmoz toolset (including OSE) I love the following tools:
SEMrush - keyword research tool
Raven - general SEO tools similar to SEOmoz but different. For example, they have a link tracking solution to track all links to a site.
AHREFs - new tool designed specifically to capture link data similar to OSE
WooRank - site evaluation tool which has lots of potential and is actively being worked on. Note, the tool has numerous bugs or questionable data but is still quite helpful and is very customizable.
Majestic - offers a toolset similar to Raven
Screaming Frog - site crawler
It is important to understand all current SEO tools I have used are just one tool in an arsenal of knowledge, tools and experience used by SEOs to perform their job. A SEO tool does not make one an SEO consultant any more then a wrench makes someone a mechanic. Many tools have seem simple but they have nuances and various limitations which are learned over time through constant use.
The above tools are all paid tools. There are numerous other tools for everything from comparing headers, generating site maps, generating heat maps, etc. A large book can be written strictly focusing on SEO tools. There is a lot of ground to cover.