What type of business software you you use??

Not digitizing software, I am interested in what you use to handle your finances, quotes, taxes, etc...

Quickbooks is the "defacto standard" though most people have reservations about it and hate it in one shape or another. They have positioned themselves as a monopoly almost. There are alternatives:
http://www.techrepublic.com/blog/five-apps/five-alternatives-to-quickbooks-for-business-accounting/1160

That includes some free open source option(s).

I do computer consulting and I often hear of people's frustrations with QB's. They also force you to upgrade all the time with planned obsolescence which I find dirty at best.

"you don't need a hook for the worms to dance."