Now, let me dispel the knee-jerk reactions to the title of this review: Pinkie Pie is a good and complex character, like ALL of the Mane 6 and I appreciate this. It's just that her complex personality grates on me as she is a loudmouthed, attention-seeking pony who is able to make herself the center of attention with impunity because so many ponies like this personality. I, on the other hand, am more like Cranky in that I am a loner who likes his quiet time over an over the top party; making his frustration with her throughout the episode very understandable and making him a highly sympathetic character to me.
Now, there is a moral to be found at the end (and a very good one at that), and this would usually be enough to salvage the show from many a problem I have with them. But Pinkie's behavior throughout the episode almost completely contradicts the lesson she supposedly learns from it. Her actions (Barring a few) border on complete lack of empathy for Cranky and his own personal boundaries, to the point of destroying something very dear to him and being upset that he isn't interested in being her friend instead of the fact that she did something wrong. I know that the moral is that your personalities don't need to match to be friends, but you also need to be respective of the other party's differences from you, something that Pinkie wasn't doing.
And, like many of the other posters, I find the reveal of Matilda at the end to be a cop-out of the highest order; meant SOLELY for the benefit of Pinkie Pie to get her exactly what she wanted no matter what.
I'm very sure there's a way to do this sort of episode right; but, sadly, this wasn't it.