Net Index is a free service that ranks and compares download and upload speeds, quality of broadband connections and internet service providers across the globe using data obtained from the popular Speedtest.net and Pingtest.net online tests.
The Net Index takes a little work to wrap your head around when you first visit the site, but it's full of useful information if you take a little time and start drilling down into its offerings. For example, the front page starts with the Household Download Index, which rounds up the average download speed across the globe and highlights the average speed by country (at 9.87Mbps, the US is above the global average of 7.59 but below the seriously high speed countries, like South Korea's mind-blowing 31.38).
From the front page, you can drill down into countries or states for more information about the cities and ISPs providing the fastest connection — much more interesting for consumers looking for the best ISP in their area. For example, here in California, I can see that if I want the consistently fastest downloading ISP, I'd probably want to go with Charter — followed by Comcast and Road Runner.
I can also see that each of the three fastest ISPs are rated around 3 out of 5 stars by customers. Cox, the fourth fastest, has 4 stars (rounded up) — something to keep in mind when I'm making my decision. Download speed isn't the only thing that matters, and the site performs the same analysis using upload speeds and a "quality index" based on results from Pingtest.net.
Give it a try and let's hear how its measurements seem to match up with your ISP — and whether it looks like you might want to switch — in the comments.