Whether you need a simple system or a complex one, you can find which systems provide the required help desk functions at hxxp: support-software. org

But raw functionality is not enough does not answer questions such as how easy it is to customize the system, whether the vendors is responsive, etc.  Here is an article that describes how to answer these questions: hxxp: ezinearticles. com/?How-to-Pick-the-Right-HelpDesk-Software---Introducing-an-Enhanced-Selection-Process&id=4496929

If you follow these steps, you will not only find the support software that meets your particular needs, you will also get it at the best price and minimize your risks.

I recommend AJ Help Desk which is the best help desk software.  
hxxp: www. ajhelpdesk. com

Recommend PHPKode helpdesk X, which is a simple web based help desk software, it is only worthy of $21.
You can find it on codeyoucon. net

FocalScope Help desk ticketing System and Live Chat software has a comprehensive ticket history to trace all interactions with customers over tickets & chats.  You can integrate your SLA’s and have the ticket queue automatically distribute incoming tickets to available agents.

The built-in chat enables agents to discuss a new customer issue with other departments for quick resolution.
It has a familiar interface similar to Outlook and integration with your ecosystem is a snap with our API.  FocalScope is offered as a cloud-based or on-premise solution to meet your needs. 

It runs on SQL 2005/2008 technology to ensure a stable, fast and expandable solution for business communications. 

FocalScope’s access from anywhere design lets you connect your remote offices and branches to a central point to form one virtual organization.

The price is competitive @ $39/agent and it’s free for the first license.