I would underscore some of what Pedanticistt said.
1. Extremely good fit with one of the profs. Such a strong fit that the Prof remarked on it too. I kind of feel like I'm mini!Prof. This is also the main reason I applied to the school and my proposed dissertation project involves looking at one of his earlier texts (foundational to the field) and examining how it can be brought current to modern technology and practices. I also think there are not a whole lot of other big profs studying this esoteric sub-field (fandom studies), so that makes the fit even more unique.
2. Prof remarked on how strong my writing sample was. He said that almost no one is really doing research at that particular intersection (fandom and race, specifically cross-racial cosplay) and that one of the big journals in the field had been looking for material of this sort and not finding it.
3. Prof also mentioned that an MA in Performance Studies from NYU was "no small thing." or something to that effect.
4. My biggest weakness was a low undergrad grade point average and Prof asked how he might defend that in the room. I explained that three big factors contributed to it. One, I went through some depression in undergrad and that had an adverse effect on some grades. Two, I struggled with some classes (inducing languages) that were outside of my major and later eliminated from the school curriculum (i.e. if I had been class of 2010 and not class of 2009, my transcript would have looked very different). I also explained how I would tackle the language issue differently in grad school. Three, I said honestly that in undergrad I had an attitude that was shaped by people telling me those were supposed to be the best years of my life, so I was determined to enjoy them. Prof really resonated with that and said he had a similar undergrad experience.
So TL:DR -- Strong fit and writing sample (with good research area) got me the interview. Interview gave me a chance to confirm awesome fit and defend weaknesses.
Thanks!