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.
Not very easy to use, requires a lot of thought and I want such tools to be intuitive. Because of that, I think I ended up not using a lot of features - not knowing how. Overall was happy when we moved on to something else.