I'm a little biased. I prefer the additional controls, options and multiple windows you get with Quickbooks on your desktop. Also, for multiple businesses, you can run all on the same purchased program (1 time fee). The On-line version has been steadily improving (adding inventory and custom forms) and you can't beat it if you have multiple users and you want to avoid a centralized server.
So, which do you use?
If you have several users who work remotely, Online is a good bet. Payroll service is also very economical.
If you are a more sophisticated user and need multiple custom forms, the PC versions are very robust.
How can I help you leverage your version of Quickbooks to run your business?