Wrike is very fast, has excellent Gantt charts, tasks can belong to more than one project, has a 3-pane display, email integration, and collaborative editing of task descriptions using EtherPad
Basecamp sets the standard for ease of use and also importantly in data sharing with other applications. It would even be better if they told developers when they change their API!
Wrike is very fast, has excellent Gantt charts, tasks can belong to more than one project, has a 3-pane display, email integration, and collaborative editing of task descriptions using EtherPad