I've been using very few Active Directory Queries over the years. I use them just to keep tabs on what devices I have where and etc. Simple things like

Displaying user accounts whos passwords don't expire.
Locked out users.
Locked out computers.
Exchange users
Operating system version and service pack levels.

Then I have some broken down just for specific OUs. Most of the time I want to look at ALL info, but sometimes, I just want to query a specific OU.

What queries do you use? What are the most helpful?

Is there anywhere that you know of to import useful query templates to modify for your organization.

If you don't use the built in query tool, then what do you use?

I have and use some of the tools from bindview. However, my network is growing far too fast to keep up with licenses. I'm always having problems with the software and spend hours on the phone with support. When it works, it works well. Just getting it to work is the problem. Not to mention it is expensive! The auditors like the reports it creates...