In an artcile byt he Associated Press in Yahoo news, the top 10 report is as listed:
(The list reflects popularity primarily based on individual visits)
2. Ocoee River, Tennessee.
3. Nantahala River, North Carolina.
4. New River, West Virginia.
5. Deschutes River, Oregon.
6. Pigeon River, Tennessee.
7. Snake River, Wyoming.
8. Colorado River, Colorado.
9. American River, South Fork, California
10. Kennebec River, Maine.
There you have it. The official Top 10 list. Rafting America partners already operate on all of these rivers. So if you want a good white water rafting trip, just go to Rafting America.