SmartDraw - Instead of starting with a blank screen, SmartDraw gives you the exact template you need.
Salesforce - CRM software solutions and enterprise cloud computing from salesforce.com, the leader in CRM and platform as a service.
Signavio - The Signavio Process Editor was created in order to be very intuitive and easy to use.
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
Padlet - Visual boards for organizing anything.