Which is the best jQuery rich editor? Any recommendation?
You can't really answer that question, it's like asking, what is better, vi or emacs?
NetBeans features native JavaScript "rich editing" including support for many libraries like jQuery. Take a look at this page: http://wiki.netbeans.org/Ajax
Avidansoft has a pretty good looking text editor. Have not tried it out, but here is the info: http://avidansoft.com/dsrte/
There are quite a few other plugins visible here for more ideas: http://www.noupe.com/ajax/37-more-shocking-jquery-plugins.html
WYMeditor is implemented in jQuery. Its nicest feature (and most controversial, I guess) is that it concentrates on semantic markup and less on visual markup. It's ideal for a corporate CMS/blog, where the user should not be able -- or at least not encouraged -- to violate corporate design guidelines. If you're goal is to expose a MS Word-like interface, TinyMCE may be a better fit. It doesn't use jQuery, though (but also doesn't interfere with it).