SharePoint 2010 Limited Web Part Selection

Scenario

• You are working in a sub-site that does not inherit permissions.
• You want to add a web part from any Category other than "Lists and Libraries"
• You are not a site collection administrator, but do have full control on the current sub-site.
• You do not have access to the site-collection root.

Issue

• The other web part categories do not show up after clicking "Add Web Part"

Resolution

• You need at least view-only access at the site-collection root level to see the additional web parts.  
• These web parts are located in the site-collection web part gallery, which you need access to.
• Alternative: Consider making the sub-site a site collection via a managed path rather than a sub-site in order to completely isolate permissions from the root site.