What is your favorite CRM?

I have tried so many CRMs… can never decide which one I like best. Also, I prefer cheap or free :) (because there are so many now).
Examples: Asana, Hubspot (free one), Zoho, Bitrix24 (I have been using that for PM as well, its going well, and free).

Let me know and tell me why it is your favorite :)
Thanks!