A better question would be &quot;What&#x27;s the least bad for my situation?&quot;<p>Are you a brand new business, or mid sized, or at a large corporation?  Each of these use cases have CRM programs that fit that niche; as well as what data you want to retain, flexibility of the system and their API&#x27;s and a host of other use cases.<p>SugarCRM seems to be the heavyweight when it comes to the DIY&#x2F;Startup crowd. 
InfusionSoft is more of an SMB or Midsized Business program, allowing for by organization purchasing, instead of by seat, which can be helpful.  
Microsoft CRM is great if you&#x27;re a heavy Windows environment, but performs poorly on OS&#x27;s outside the Microsoft walled garden (although that is supposed to change a bit with CRM 2016).
SalesForce has some of the best plug-in integration, so if you want a solution that probably will integrate with your other marketing software rather seemlessly you&#x27;ll find none better.
SAP &amp; RightNow tech (both under the Oracle umbrella now) are the heavy hitters, allowing for large, complex organizations with expansive and diverse customer bases to be able to handle CRM aspects rather seemlessly.<p>Hope this helps a bit.