Jira may be extremely sluggish and require a large amount of memory on the client side.
Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.
Usersnap - Usersnap is a customer feedback software for SaaS companies that need to constantly improve and grow their products.
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.
zipBoard - ZipBoard is a web-based visual bug tracking & issue tracking tool that helps developers, testers and project managers collaborate during website and elearning development.
Basecamp - A simple and elegant project management system.
Redmine - Flexible project management web application