At first, I have through that she was a troll before watching the show; however, I had watched it, and, apart from getting those throughts that she was a troll deleted, Celestia has grew on me to become one of my fave characters, and my favorite Princess, because, you'd gotta love her cuteness, her kindness and her sense of humor, am I right?
And a pretty bad person; and that's because one of two: Or they did watched only the memes, or they did misunderstood Tia's things that she did on the show. PS: I like her sister too, specially on Chapter 2x04, when she talked with the Royal Canterlot Voice, and when she scared the kids. She was cool there, seriously... but still, I prefer Celestia.
Nightmare is cool...in the I'll take over Equestria because my sister banish me to the moon for reasons bronies will not know sense...but that's just me. Still, Nightmare Moon is cool too. I'm moree to Twilight Sparkle, heehee.