SEOmoz has helped quite a few companies and websites drive significant traffic to their sites. They use these effective methods which they now share with the blogosphere.
#10 – Targeting Unmonetized Searches
#9 – Creating Controversy
#8 – Maps & Mashups
#7 – Event Coverage
#6 – Top Ten Lists
#5 – Online Tools
#4- Graphic & Web Design
#3 – Leveraging Social Networks
#2 – Blogging & Blog Comments
#1 – Reporting Remarkable News
#0 – Offering Something Incredible
You may find their breakdown useful on their original article, 10 Remarkably Effective Strategies for Driving Traffic.