My opinion for who is "best" is that it's a matter of perspective. Before reading this thread, I would have answered Fluttershy without a second thought and moved on. But weesh said that "best" was "what criteria people are using to define 'best'", or as I interpret: "what's your definition of 'best?'" My definition: Who I most likely hang out with the most if I met the mane 6? My answer: Twilight Sparkle. The reason: She and I share common interests, at least more so than the rest of the mane 6. While some of the other ponies would be fun to be around, most of what they do bugs me or I'm just simply not good at. Dash likes racing, and I'm probably the least athletic kid I know, AJ would most likely be working on the farm, applebucking, Rarity would be doing something with fashion, which I'm not a huge fan of, Fluttershy would be doing something with animals, which is again something I dislike, and Pinkie's WAY too hyper for me.That leaves Twilight, who I imagine is probably studying something or another, and although I don't like to study I could occasionally have an intelligent conversation with her, and maybe learn something in the process, plus she has a ton of books, so in the event I got sent to Equestria, I could maybe learn something about their world. Not saying the others are dumb, I'm just saying Twilight is probably the smartest.