Given that Asia dominates the list of 100 Fastest Internet cities and China is the most populous nation in the world, it shouldn’t come as a surprise to anyone that China is home to the largest broadband service provider in the world. The latest data gathered by Telegeography, a research firm, shows that at the end of the first quarter of 2010, China Telecom led the top 10 broadband service providers rankings. It was followed by China Unicom.

The two Chinese ISPs account for nearly 20 percent of the world’s broadband subscribers. At the end of the first quarter of 2010, there were close to 492 million broadband subscribers worldwide, Telegeography notes. (Related: there are nearly half a billion broadband subscribers worldwide.)

China vs US

The rise of these two carriers also mirrors the rise of China as an Internet behemoth, pushing the U.S. into the second spot. The United States had four broadband ISPs in the top ten list: Comcast (s CMSCA), AT&T (s T), Time Warner Cable (c TWC) and Verizon (s VZ). Korea Telecom cracked the top 10 and edged out Telecom Italia, pushing it to the No. 11 spot.

These top 10 broadband service providers in total account for roughly 39 percent of world’s total broadband customers, and they collectively added about 23.3 million new subscribers between the first quarter of 2009 and the first quarter of 2010.

Who’s The Best Performing ISP?

While sheer size and scope matters, it’s also important to check out a service provider’s actual performance. Many ISPs make wild bandwidth and speed claims, but deliver a suboptimal performance from their broadband connections.

Ookla, the Seattle, Wash.-based company behind the popular Speedtest.net web service, has developed a new methodology (announced yesterday) that shows you the actual performance of broadband service providers from an end-user’s perspective.

“The new ISP ranking data takes a giant step in that direction, further empowering consumers for the first time with rich data that helps evaluate ISP performance close to home or throughout the world,” Ookla co-founder Mike Apgar said in a statement.  With nearly a million speed tests a day, Ookla has a good idea about which ISPs are performing well and are true to their claims. According to Ookla, U.S. ISPs deliver an average download speed of 9.9  Mbps while Chinese ISPs deliver an average download speed of 3.5 Mbps. South Korean download speeds, meanwhile, are around 31.5 Mbps.

How do U.S. broadband service providers rank? Ookla says Comcast is the best broadband provider in download speed terms, with an average download speed of 16.26 Mbps, while Time Warner Cable has an average speed of 13.48 Mbps and Verizon has an average of 10.76 Mbps.

Here are the top ten broadband service providers in the US based on download speeds.

1. Comcast 16.26 Mbps

2. Charter Communications 15.06 Mbps

3. Midcontinent Communications 14.36 Mbps

4. Optimum Online (Cablevision) 14.31 Mbp

5. RoadRunner (Time Warner Cable) 13.48 Mbps.

6. Cox Communications 13.41 Mbps

7. Insight Communications 11.75 Mbps

8. Surewest Broadband 11.44 Mbps

9. Verizon 10.76 Mbps

10. Prairiewave Telecommunications 10.52 Mbps.

You can see clearly that cable companies dominate this list.

According to Ookla, in the U.S., the average monthly cost for broadband is at $47.32 or about $5.06 per megabit per second. In California, broadband costs just $4.24 per Mbps, while residents of Idaho pay $8.80 per Mbps, Washington respondents averaged just $3.89 per Mbps and Michigan subscribers pay $6.36.

Broadband Image courtesy of Flickr user Gavin St. Ours