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.
Timewatch - Timewatch offers time tracking, expense management, resource scheduling and professional services automation solutions.
Basecamp - A simple and elegant project management system.
Office Timesheets - Professional Services Automation
Teamgantt - Intuitive project planning and collaboration. Beautiful Gantt charts, task-level communication, file sharing, resource management and more.
Krow - Krow Software is a professional service automation solution.