For the first almost 4 years I was my current place we did not have a ticketing system it was all email/phone call and it was easy to lose track of things. Also being the only person on the helpdesk did not help matters. Now that we have one I see how necessary and important it is. It needs attention it needs a ticket it took some user training but most people are now pretty in line with using it.
We now use Solarwinds WebHelpdesk we atucally had purchased it just a few months before Solarwinds bought out the original vendor Macs Design Studio. It works pretty well but there are some improvements needed on how it handles process workflows and change management voting.