Well. I like My Little Pony. I've liked it since I was little, which, if anyone's keeping score, makes me better than people who only started liking it after the new show came out. A more detailed account of my MLP experience can be found on my other, more better MLP thread, if anyone can be bothered to find it.
Anyway, FiM is a good show. The "best pony" is a silly question, because it basically suggests that characters should be put in a linear order of goodness. I find a tier-based system works best. And here are the tiers:
Best Pony tier: Twilight Sparkle. Twilight is basically objectively the best pony, being the main character.
Tier 2: Rarity and Rainbow Dash. These are the best members of the main cast who don't have the main character ability to be best. The tier system works here, because picking one over the other is hard.
Tier 3: Applejack and Pinkie Pie. This tier really demonstrates the power of tier system. Applejack is clearly better than Pinkie, but not enough that anyone should care or even really distinguish between the two.
Tier 4: Spike.
Tier 5: Celestia and Luna. Celestia is way cooler, but Luna is baller as well.
Tier 6: Background ponies. Okay. If a background pony is your favorite pony, here's what you do. Take a pencil. Put it between your middle and ring fingers. Now squeeze those fingers together really hard. Does it hurt? Then you did it right. That's your punishment for liking a flash vector instead of a real character, you pleb.
Tier 7: The Armenian genocide.
Tier 8: Fanon. If you like the fanon surrounding background ponies more than real characters, follow the steps prescribed in tier 6, but continue the process until you die of starvation.
Tier 9: The concept of human rights violations.
Tier 10: Fluttershy. Fluttershy is the worst pony and I basically despise her more with every passing moment. There are three reasons to like Fluttershy:
1, you're ignorant. You haven't seen much of the show. She's decent in the early episodes.
2, you're stupid. Plain and simple. You see all of the show and are too dumb to not like her.
3, you're a bad person. So let's say you watched all the show and are smart. You still like her. Well, it's because you're bad. Not like bad taste (probably that too, though). As in morally bankrupt. The only other reason to like this character is actual malice.
Anyway, the show's good, but bronies are somehow worse than most fandoms. The fan community sucks . Fan music sucks. All fanfiction ever sucks. Most fanart sucks. Fanon sucks.
Good show, though.