If your developing Ruby on Rails web apps on Windows (or any platform really) why not try RadRails
The IDE itself is running on top of a very light version of Eclipse, it allows database queries to be fired off right in the console and has integrated support for working with subversion repositories. Its promising all you could ask for under one roof.
I came across this recently and first impressions are good. There is even a blog and podcast you can follow on its development.
