Rock star because it would be nice to share your music with a whole audience of people (even though I would get really nervous because of the big crowd and I don't have that many creative juices).
Be a pony.
Have the ability to go between Equestria and Earth when I so choose.
Picked a different choice. If I went to Equestria, I would like to be friends with ponies and stay friends with them when I go back and forth.
Picked a different choice because it would be interesting to explore what it's like to be a pony.
Picked a different choice. It would be crazy and awesome if this stuff happened in real life.
I like Rainbow Dash, but this was way over the top for her, even though she really wanted to meet and seek admiration from her idol, which she eventually did (sorry for the spoilers for those who haven't seen the episode yet).