Bitrix24 suits even the largest enterprises with a highly complex workflow. Why is Bitrix24 one of the best free hosted CRM? Available BOTH in cloud and on premise (a.k.a hosted CRM and self hosted CRM).
Second, it comes with over 35+ free sales tools, including client management, inventory, pipeline management, product catalog, virtual call center, videoconferencing and much more.
Finally, it's highly customizable - you can change forms, add fields, company logo and so on. Open source code is available in the self hosted edition.
* Please note that the information may have changed since the publication. For current prices and features please visit Bitrix24 pricing page.