The lowest I've made was at 1.032 and it was a very light blonde ale, made to share with some non-craft beer drinking family and friends. Turned out pretty good - no off flavors, light, crisp and refreshing.
http://www.singingboysbrewing.com/Drinkability-isn-t-a-word.html
http://www.singingboysbrewing.com/Drinkability-isn-t-a-word.html