Just can't seem to find any controversy in this thread...
Actually, Quickbooks Pro is as far as I've gotten with anything professional. I've been using MS Works for my billing, accounting and estimates for the last two years!
Then I discovered that it would be so much easier if my materials database was actually linked with my invoices... No more "CTRL-F", Find X, Copy-Paste, Alt-Tab, etc. etc.
Just start typing a catalogue # and it fills in the rest!
Neat!
Move along folks, nothing to see here...