I'd love to use HelpScout. I prefer not to use ZenDesk or Desk.
Ideally I would like to see ticket history associated with the Contact - Account in my PD views. Are there any helpdesk integrations that support this level of detail?
Help Scout looks very clean.
Not sure of your industry but if it is remotely connected to e-commerce, you should check out Gorgias and DelightChat.
You can also try FreshDesk.
There's also Trengo.