My business is specialized. It requires adaptability on the part of the contact and management software I use. Chaos Intellect has project pages which completely shift into my mode/requirements/custom fields, etc. rather than demanding I adapt to strictly laid out parameters usually found in other similar software. And via this project page, my client info, emails, notes, linked files and anything else related to a project are easily available at the click of a key. I am just now promoting it to others in my field simply because it serves the purpose of more than one software due to its inherent flexibility.
Stability, flexibility. Rather than have the owner adapt to it, the software adapts to the client. Still discovering its "amazingness" after 25 years.
Still trying to find something.