pinkie pie is the best of the six pony friends. 

she is not just about partys if u really think about it balloons is the worst thing for her cutie mark and the best at the same time. yes she can throw amazing partys but she also can do so much more. she is funny and kind and adventureous. she makes people smile. pulls pranks. makes goodies, pinkie pie can even move rocks.

Mane six got swag pinkie pie by l0gun-d5qapcy

But pinkie pie needs help to remeber her self and her friends thats where her friends help her remember all of those things. She also helps her friends know what having fun and laughing is all about.

like she shows her skills of laughter in the first ever episode when she shows the gang of ponys that if you laugh in the face of fear nothing can stop you.

but in the episode party for one she forgets that her birthday was that day and thinks her friends are making up lies so they cant attend her after birthday party for her toothless aligater Gummy.

as you can tell by her cutie mark (the 3 balloons on her flank ( thigh thing ))
Pinkie pie poster