I'm trying out another ticketing system for work. We need something that will manage internal support tickets as well external access for customer service. I've done quite a bit of research and decided to try out JitBit Help Desk. Its free to try and only about $380 for the full version (if you host it locally, which I am).
If it doesn't work out, ZenDesk looks really good. Unfortunately its a subscription service and I'd rather not add anything else to our monthly bills.