About every couple of months I run a speed test on my broad-band connection to make sure that everything is running properly and my ISP is providing an adequate level of service.
I never had one web site that I would always go to - to do a speed test. Typically I would do a Google search for "online Internet speed test" and find one that seemed to be doing an adequate job.
Today, I came across SpeedTest.net and I must say that I really like the site and it will become part of my arsenal of tools.
SpeedTest has one of the best interfaces for a speed tester. In addition it stores information about your last tests as well as allows you to compare your results with other ISPs and rate your own ISP. For those who might be interested, there is one version of SpeedTest that you can include on your web-site and another version that allows you to rebrand SpeedTest for commercial purposes.