I liked their attempt at defining indie rock:

A top summary of our definition of indie rock might read something like this: Indie rock is primarily an American musical art form that began in earnest around 1980, started to really take shape in 1988, and has since splintered into many forms. It started as a musical byproduct of punk rock and became a commercial product in pop culture. With rare exceptions, there should be guitars, drums, and a singer. With no exceptions, it should be released on an independent label. (Well, with one exception.) It should speak to and incorporate other genres without fully becoming another genre. It tends to be made by people who are apart (or set themselves apart) from mainstream culture, and therefore tends to be associated with losers and depression, or cool kids and art school. It should, by some estimation, rock.

Per any Top 100 lists, the comments are an integral amendment to the thing itself. These don't disappoint!