At the moment, my invoices are an Excel template. My proposals are Word templates, and my CRM is my Google apps contacts list. I'm still not very happy with that as a CRM. I augment things with trac as it has a good enough wiki to be malleable into whatever kind of pages I want.

I tried SugarCRM and found it very hard to use. The interface is borderline evil. I've previously used Tactile CRM (paid for account at a day job) and it was OK, and has its own quirks.