Mozbar
SeoBook Toolbar
SeoQuake
Open Site Explorer
Link Research Tools
Bing Webmaster Tools
SearchMetrics
BuzzStream
Ontolo (some useful tools on this site)
Citation Labs
Check My Links extension for Chrome
Domain Hunter Plus extension for Chrome
Xenu's Link Sleuth
Screaming Frog (this one looks good)
archive.org / Wayback Machine
Link Detective
Seo Tools for Excel
LinkDex
Seo Power Suite
Microsoft Seo Toolkit
LinkRisk.com
What else? I was trying not to use any of the tools mentioned above, like
SemRush.