Two words: Bucking epic~
Gyah, I don't even remember everything to write... Off the top of my head:
For some reason "My Big Brother Best Friend Forever" made me start to cry. I have no idea why. But I got my big Twilight plush and held her for a while.
Words I spoke at the end of part one: "Holy shit, did she just send Twilight to hell??" >w>
Changling Queen? Best design ever? Yes. Very yes. Please tell me those holes in the legs are a viable toy design, please please please~
Celestia actually doing something! Will wonders never cease??
I admit, I had no idea what you could do with an episode called "The Royal Wedding" and make it two parts, but, this is pretty much exactly what you do.
O hai, Luna. You didn't do much, but it was nice to see you again.
In summation, there is no way you could make this episode 20% cooler, no matter how hard you tried. It's pretty much awesome already~