As you all know it can be difficult to find out which feature you have to activate before you're able to do something. Eventually it would be nice if this Wiki page becomes an authoritive resource for this topic.

Name	Description	Site collection feature	Site feature
Access Services	http://www.loisandclark.eu/Pages/accessservices.aspx	SharePoint Server Enterprise Site Collection features	SharePoint Server Enterprise Site features
Approval - SharePoint 2010 workflow	http://sharepointresourcecenter.com/sharepoint-2010-workflows-out-of-the-box-workflows-customizations.html	Workflows
Collect Feedback - SharePoint 2010 workflow	http://sharepointresourcecenter.com/sharepoint-2010-workflows-out-of-the-box-workflows-customizations.html	Workflows
Collect Signatures - SharePoint 2010 workflow	http://sharepointresourcecenter.com/sharepoint-2010-workflows-out-of-the-box-workflows-customizations.html	Workflows
Content Organizer Rules	http://technet.microsoft.com/en-us/library/cc263464.aspx		Content Organizer
Content Organizer Settings	http://technet.microsoft.com/en-us/library/cc263464.aspx		Content Organizer
create a new Send To connection	http://technet.microsoft.com/en-us/library/cc263464.aspx		Content Organizer
disposition approval workflow	http://technet.microsoft.com/en-us/library/cc263148.aspx	Disposition Approval Workflow
document id	http://blogs.msdn.com/b/ecm/archive/2011/10/12/document-id-in-sharepoint-server-2010.aspx	Document ID Service
document set content type	http://technet.microsoft.com/en-us/library/ff603637.aspx	Document Sets
Excel Services Application	http://technet.microsoft.com/en-us/library/ee424405.aspx	SharePoint Server Enterprise Site Collection features	SharePoint Server Enterprise Site features
Group Calendar	http://office.microsoft.com/en-us/sharepoint-server-help/use-a-group-calendar-HA101810606.aspx		Group Work Lists
InfoPath Forms Services	http://technet.microsoft.com/en-us/library/cc262263.aspx	SharePoint Server Enterprise Site Collection features
Metadata navigation settings	http://technet.microsoft.com/en-us/library/ff608067.aspx		Metadata Navigation and Filtering
Open document in the client application	http://technet.microsoft.com/en-us/library/ee837425.aspx	Open Documents in Client Applications by Default
publishing approval workflow	http://office.microsoft.com/en-us/sharepoint-foundation-help/all-about-approval-workflows-HA102280698.aspx	Publishing Approval Workflow
Rule content type	http://berg-henry.blogspot.com/	Document Routing Resources (hidden)
Site Collection Help library	http://office.microsoft.com/en-us/sharepoint-foundation-help/add-custom-help-to-a-site-collection-HA101833141.aspx	Custom Site Collection Help
site collection output cache	http://technet.microsoft.com/en-us/library/cc770229.aspx	SharePoint Server Publishing Infrastructure	SharePoint Server Publishing
Managed Metadata column	http://technet.microsoft.com/en-us/library/ee424402.aspx	Taxonomy feature (hidden)
three-state workflow	http://office.microsoft.com/en-us/sharepoint-server-help/use-a-three-state-workflow-HA101793530.aspx	Three-state workflow
Visio Services	http://technet.microsoft.com/en-us/library/ee663485.aspx	SharePoint Server Enterprise Site Collection features	SharePoint Server Enterprise Site features

Also see this page for all features: http://sharepoint.microsoft.com/en-us/product/Pages/Features.aspx