OK, I'm looking for good examples of how to design a navigation system for a business site. I'm looking for the following criteria in the menus:

* Good use of color/contrast

* Can handle at least 3-4 levels deep (e.g. Cars > Domestic > Ford > Models).

* Easy to use!

* Preferably a horizatal menu across the top. Side bar navigation menus take up precious horizontal space. The site will be mostly forms and will need a lot of the horizontal space. Please give examples of good side bar menus as well though.

Pluses:

* Dynamic Menus

Just to get you started:

http://www.sap.com
http://www.sybase.com