HelpSpot - Help Desk Software > Help Desk Portal

It doesn't appear free... but looks like it has a nice clean interface...

HelpSpot - Help Desk Software > Help Desk Portal

"HelpSpot The unique design and workflow enables your support staff to solve problems the first time and easily manage many requests from multiple sources. Beyond simple help desk software, HelpSpot is an entire web based help desk portal; Providing your customers with powerful self-help functionality that drives down cost and improves the customer experience."