A full CRM tool with all the features I could ever want. I love the no-developer management approach allowing me to implement any changes I want. However with so many options, it does take a while before you feel like you are utilizing everything.
Salesforce is the best CRM I've ever used. Its easy to navigate between multiple accounts, and manage leads between sales teams. The daily generated reports are essential for my day-to-day work.
I use Salesforce daily to run our business. It let's us build out new functionality extremely quickly and relate data to build a better picture our our business.