Top 50 Ruby on Rails Websites
storecrowd.com
storecrowd.com
Edit: I did a little digging and it looks like they used to be on RoR but switched over sometime in mid '09... so I guess that explains the mistake.
(Not sure when it was last updated, though. The wiki seems to have been spammed quite a bit :()
Is this based around some kind of science/statistical analysis?