I've used many helpdesk systems over the years, one of the best was GLASS, but that was $$$$. Osticket is just brilliant and pretty much covers everything off. There are a few tweaks that would help though...
cc's as many have suggested would be great. There are many occasions when I have to copy a ticket and paste into an email (badly) to send a cc.
printer/copy friendly view. Probably one of the easiest to do, but there are times when I need to print the ticket and/or copy/paste it into something. Right now I have to copy/paste each entry and printing always goes tits up. Just a button which returns a text/plan file to the browser with the ticket header, and contents.
SMS, was a great feature of glass, missing in osticket. Your already taking the persons's phone number, just need to give the option to send alerts via text message, and integrate with http based sms gateways (like clickatell etc).
osFAQ is great, just need to bring the two projects together imo, with the option to link tickets to FAQ's/return a FAQ link directly from a reply.
As many have suggested, link/merge feature would be great. Customers just keep raising duplicate tickets, and I've got to close/delete one, would be better to just merge it in.
Money & time; I'm sure most people run a FOC helpdesk, but some of ours is chargeable. When the ticket it closed, and if someone remembers, you need to tot up the time spent, and open a separate system to raise the billing. There is no where in osticket to flag a ticket as billable, or to record time/materials. Suggest an option to have 'chargeable' as a flag on the ticket, and with each reply, have an option to add a time/charge. e.g. If I spent 30 minutes on the phone to a customer, that's 30 mins I want to add to that reply.
Exports and Statistics; I can export the db, and produce reports by customer manually, and it works fine, but its not that simple for everyone to do. Would be great to be able to export tickets by customer, by time taken (above) so as to automate reporting to customers and ultimately billing.
One more; A customer field and customer reference would help no end in several above. Currently use the name field but its not perfect.
The above are suggestions only and in NO WAY criticism. If they make it into future releases then I'd be very happy, but no pressure :).
Thanks again for an awesome helpdesk system!