On a call last week, a client asked what CRM people were using. It's all over the map really.
Broadsoft has hooks for SalesForce, but only the premium edition.
Microsoft Dynamics is used by many Microsoft partners but it is a bear to get up and running. Afterward you can sell it to your customers! I would sell Sharepoint and Exchange with that for Collaboration and Unified Messaging.
There are no cost CRM apps like FreeCRM, Zoho, Hirise HQ and SugarCRM. Experience suggests that SugarCRM is clunky and not intuitive. Since most employees and sales people do NOT want to touch CRM anyway, get an easy to use one.
Avidian offers Prophet CRM for Outlook.
Of course, if you Google CRM reviews, you will get a bunch of results that are domains that do reviews for software they are affiliated with. PCMag has a review page here.
What are you using?