Thirding Asana. Just set up a major series of teams and projects and hooked in Zapier for some automation with a ticket system (Teamwork Desk). While Asana isn't a CRM by any means, we're creating a workflow with Kanban and automation to capture the vital interactions with clients.

Asana has the added benefit of allowing the user to interweave non-project-specific tasks to achieve something of a GTD workflow. It really helps me to get every actionable item out of my head space and assign some kind of priority / responsibility / due date to it.

Asana Premium is a must for the flexibility with custom fields (https://asana.com/guide/help/premium/custom-fields)