This Top Ten Imperial IPA or India Pale Ales list is from America's Best and  from the results of the 2009 United States Open Beer Championship.  
 
1. Anderson Valley 20th Anniversary Imperial IPA, Anderson Valley Brewing
2. Shipyard XXXX IPA, Shipyard Brewing 
3. Stone Ruination IPA, Stone Brewing 
4. 90 Minute IPA - Dogfish Head Brewery - Delaware
5. Pliny The Younger - Russian River Bewing - California
6. Bell's HopSlam Ale - Bell's Brewery - Michigan
7. Dreadnaught IPA - Three Floyds Brewing - Indiana
8. I2PA - Imperial India Pale Ale - Rogue Ales - Oregon
9. Racer X - Bear Republic Brewing - California
10. Arcadia Hop Rocket - Arcadia Brewing - Michigan

 
Imperial / Double India Pale Ale
Imperial India Pale Ales have intense hop bitterness, flavor and arom Alcohol content is high to very high and notably evident. They range from deep golden to amber in color. The style may use any variety of hops. Though the hop character is intense it’s balanced with complex alcohol flavors, moderate to high fruity esters and medium to high malt character. Hop character should be fresh and lively and should not be harsh in quality. The use of large amounts of hops may cause a degree of appropriate hop haze. Imperial or Double India pale ales have medium-high to full body. Diacetyl should not be perceived.
OG: 1.075-1.100
FG: 1.018-1.028
Alcohol by Weight: 6.0-8.4%
IBU: 65-100
Color SRM: 5-13