I use MegaIndex.com - I think currently its link database is one of the biggest and most up-to-date.
Joe Youngblood, Tool Highlight Tuesday.
I realy enjoyed it. If you are an SEO it’s a gift from above – free link data. Dig in there, get all the data, get it while it’s still free. Really great job – I love the way it is!
This report, based on regularly updated data crawled by MegaIndex, provides you with the answer to the question "How is my website doing in linkbuilding terms?". This answer is crucial for a healthy and succesful SEO strategy. Find more linkbuilding opportunities and monitor potentially damaging links that lead to your website.