Support Details gives you system details instantly
I really enjoy what have come to be known as single-serving sites. These are sites that do only one specific thing, but the best of them do that thing exceedingly well.
My new favorite site of this kind is Support Details. The URL is super easy to remember (supportdetails.com), and when you pay the site a visit, it lists a bunch of details about your computer that you can include when making a support request for software that you're having trouble with.
You can export the details as a CSV or PDF file, or you can simply email them to a recipient by using a form that's right on the site. It's simple and effective.