There is an undeniable cult that follows Bob's Donuts on Polk Street, devouring the sinkers that emerge from the deep fryer in the wee hours of the morning. Even though you can't it fresh and hot after a night of clubbing, the apple fritter at Uncle Benny's (2049 Irving) in the Outer Sunset gives Bob's a serious run for the $1.50.
Uncle Benny's nails the gradation of texture that makes a fritter truly stand out. The edges, coated in an almost wax-like shower of glazed sugar, teeter on the precipice of burnt, and the apple-chunked center is super soft and fluffy.
These fritters have transformed us into a very occasional consumer of donuts into a person we fear the Uncle Benny's cashiers now know on sight. (If so, they're at least polite enough to let us pretend like we're going to order something else.)
Incidentally, Uncle Benny's also has a surprising amount of big, puffy bagels in strange flavors (like strawberry and jalapeño) that are so blasphemous they would probably give any New Yorker a heart attack. Best to focus on the fritters.