What are the best CRMS for workflow automation?

I am working with a real estate investment company and planning to transfer their current CRM over to a new platform. We are looking for a CRM platform that is highly customizable and has strong workflow automation. Ideally, I'd like to build a system that has "decision tree" functionality. An example of this would be "If a new lead is entered into the CRM, then assign the lead to a team member and give them the task of 'call lead'." From there, I would like almost a prompt to ask the user the following "did the lead answer the phone?" If the answer is yes, it would ask the user to write notes and then automatically schedule a follow-up call into their future to-do list. But, for example, if the lead did not answer, I would want the follow-up call set for an earlier date/time so that we make sure to contact the lead before it is too late. Basically, I would like to create a decision tree automation for the entire process of the business so that the system will be followed to the T every time. Does anyone have any suggestions for which CRM would be best for this? Thanks