This Top 10 Scotch Ales list is from America's Best and Top Ten and from the results of the 2009 US Open Beer Championship.  
 
1. Old Chub - Oskar Blues Brewery - Colorado
2. Scottish Pale Ale, Neustadt Brewing - Canada
3. Satan’s Pony, South Street Brewing - Virginia
4. Robert The Bruce Scottish Ale - Three Floyds Brewing - Indiana
5. Duke Of Winship - Middle Ages Brewing - New York
6. Black Douglas Ale - Broughton ALes  - Scotland
7. St. Andrew's Ale - Belhaven Brewery - Scotland
8. Brooklyn Winter Ale - Brooklyn Brewery - New York 
9. Railbender Ale - Erie Brewing - Pennsylvannia 
10. Long Trail Hibernator - Long Trail Brewing - Vermont
  

Scottish Ale
Subcategory: Scottish Light Ale
Scottish light ales are light bodied. Little bitterness is perceived and hop flavor or aroma should not be perceived. Despite its lightness, Scottish light ale will have a degree of malty, caramel like, soft and chewy character. Yeast characters such as diacetyl (butterscotch) and sulfuriness are acceptable at very low levels. The color will range from golden amber to deep brown. Bottled versions of this traditional draft beer may contain higher amounts of carbon dioxide than is typical for mildly carbonated draft versions. Chill haze is acceptable at low temperatures. Though there is little evidence suggesting that traditionally made Scottish light ales exhibited peat smoke character, the current marketplace offers Scottish light ales with peat or smoke character present at low to low-medium levels. Thus for the purpose of this competition a peaty/smoky character may be evident at low levels.
OG: 1.030-1.035
FG: 1.006-1.012
Alcohol by Weight: 2.2-2.8%
IBU: 9-20
Color SRM: 8-17 
 
Subcategory: Scottish Heavy Ale
Scottish heavy ale is moderate in strength and dominated by a smooth, sweet maltiness balanced with low, but perceptible, hop bitterness. Hop flavor or aroma should not be perceived. Scottish heavy ale will have a medium degree of malty, caramel-like, soft and chewy character in flavor and mouthfeel. It has medium body, and fruity esters are very low, if evident. Yeast characters such as diacetyl (butterscotch) and sulfuriness are acceptable at very low levels. The color will range from golden amber to deep brown. Bottled versions of this traditional draft beer may contain higher amounts of carbon dioxide than is typical for mildly carbonated draft versions. Chill haze is acceptable at low temperatures. Though there is little evidence suggesting that traditionally made Scottish heavy ales exhibited peat smoke character, the current marketplace offers many Scottish heavy ales with peat or smoke character present at low to low-medium levels. Thus for the purpose of this competition a peaty/smoky character may be evident at low levels.
OG: 1.035-1.040
FG: 1.010-1.014
Alcohol by Weight: 2.8-3.2%
IBU: 12-20
Color SRM: 10-19 
  
Subcategory: Scottish Export Ale
The overriding character of Scottish export ale is sweet, caramel-like, and malty. Its bitterness is perceived as low to medium. Hop flavor or aroma should not be perceived. It has medium body. Fruity-ester character may be apparent. Yeast characters such as diacetyl (butterscotch) and sulfuriness are acceptable at very low levels. The color will range from golden amber to deep brown. Bottled versions of this traditional draft beer may contain higher amounts of carbon dioxide than is typical for mildly carbonated draft versions. Chill haze is acceptable at low temperatures. Though there is little evidence suggesting that traditionally made Scottish export ales exhibited peat smoke character, the current marketplace offers Scottish export ales with peat or smoke character present at low to low-medium levels. 
OG: 1.040-1.050
FG: 1.010-1.018
Alcohol by Weight: 3.2-4.2%
IBU: 15-25
Color SRM: 10-19