ZohoDesk offers a good value for money, scalability and integrations.
It's a good solution that encapsulates not only the so-called normal ticketing system, but it will allow also you to have a chat platform. It also offers, as a big plus, a solution for telephony included in the "professional" package. One of the elements that made their offer much more convenient is the "light agent" seat count.
For a very reasonable price, the solution perfectly meets the primary needs of a service desk, Even though it takes time, once properly configured, the solution can meet all types of service desk needs (filters, reports, analytics, SLA management, automation, etc.)