This Top Ten Bitter list is from America's Top Ten and from the results of the 2011 US Open Beer Championship.  
 
1. Neustadt Bitter - Neustadt Springs Brewing, Ontario, Canada
2. First Draft - Niagara College, Ontario, Canada
3. Happy Hour Hero Ale - Montana Brewing, Montana
4. Bluebird Bitter - Coniston Brewing - England
5. Honker's Ale - Goose Island - Illinois
6. Brakspear Bitter - W.H. Brakspear & Sons England
7. Arkell Best Bitter - Wellington Brewery - Canada
8. Best Bitter - Dick's Brewing - Washington
9. Royal Oak Traditional Bitter - O'Hanlon's Brewing - England
10. Samuel Smith's Old Brewery Bitter - Samuel Smith - England
    

Bitter
Subcategory: Ordinary Bitter
Ordinary bitter is gold to copper colored with medium bitterness, light to medium body, and low to medium residual malt sweetness. For the purposes of this competition, either English or American hop flavor and aroma character may be evident at the brewer’s discretion. Mild carbonation traditionally characterizes draft-cask versions, but in bottled versions, a slight increase in carbon dioxide content is acceptable. Fruity-ester character and very low diacetyl (butterscotch) character are acceptable in aroma and flavor, but should be minimized in this form of bitter. Chill haze is allowable at cold temperatures.
OG: 1.033-1.038
FG: 1.006-1.012
Alcohol by Weight: 2.4-3.0%
IBU: 20-35
Color SRM: 8-12
 

Subcategory: Special Bitter or Best Bitter
Special bitter is more robust than ordinary bitter. It has medium body and medium residual malt sweetness. It is gold to copper colored. Hop bitterness should be medium and absent of harshness. For the purposes of this competition, either English or American hop flavor and aroma character may be evident at the brewer’s discretion. Mild carbonation traditionally characterizes draft-cask versions; for the purposes of the bottled entries entered in this competition, normal or a slight increase in carbon dioxide content is acceptable. Fruity-ester character is acceptable in aroma and flavor. Diacetyl (butterscotch character) is acceptable and characteristic when at very low levels; the absence of diacetyl is also acceptable. Chill haze is allowable at cold temperatures.
OG: 1.038-1.045
FG: 1.006-1.012
Alcohol by Weight: 3.3-3.8%
IBU: 28-46
Color SRM: 8-14