CMS plugin/gem

Plz suggest the best CMS plugin/gem.

Radiant (http://radiantcms.org/)
Also, you have Comatose (http://code.google.com/p/comatose-plugin/)

Hope this helps

If you want to use radiant with an app, you may want to look at RadiantOnRails.

http://radiantonrails.rubyforge.org/

personally, I am a big fan of comatose, and am using it in several apps.

-Andrew Kuklewicz