Ask HN: Freelancers – your preferred CRM and Project Management stack?

A question to all of the freelancers and small (<10 people) service businesses which frequent Hacker news:

What is your preferred stack of tools for handling Project management, CRM, time tracking, invoicing, expenses etc...?

In the past I have used "Pancake app"[1], which served the needs of my team and I quite well. One of its key advantages is that it offers a "one stop shop" for many of these tasks.

Recently, however, I have been looking around at more dedicated solutions for each task which would (hopefully) offer better integration with an existing workflow (github, payroll, recurring tasks etc...). Do you have any vital tools which your business depends on?

[1]: http://pancakeapp.com/