#1. Rainbow Dash is forever 20% cooler than the next coolest pony. This is an indisputable and measurable scientific fact. You can buy a cool-o-meter at your local hardware or electronics store and measure it yourself; just remember to turn down the sensitivity as Rainbow's inherent awesomeness can sometimes fry the cheaper ones. You'll find she is always 20% cooler than any pony in her presence. That's right, if another extraordinarily cool pony, like say Applejack, walks into the room, Rainbow simply becomes that much cooler. Next point! #2. Rainbow Dash currently holds the record for Kicking Dragons. You know what that record is? "1". Yup, Rainbow is the only pony to blatantly kick an adult dragon--IN THE FACE no less. People like to mention that Rarity is the first to throw a kick in the whole show, but you know what? Dragon makes your manticore invalid. Moving on! #3. When Rainbow is doing her thing, GUITARS HAPPEN. I mean awesome rockin` electric guitars--which always make everything even more awesome! Or does Rainbow make electric guitars awesome? One of those chicken or the egg things, I guess. Maybe both Rainbow and guitars are two parts of the coolness-continuum-complex? DOESN'T MATTER. What does matter is that every time Rainbow is showing off, there are some epic guitars rifts playing. It's like her theme instrument or something. So I hope that I have achieved my noble goals of educating you all about Rainbow Dash, the only realistically best pony. Rainbow fans should now be aware of exactly why Rainbow is their favorite. And for those of you who thought other ponies were best? I hope you learned your lesson, but don't worry about it too much; We all make mistakes. Rainbow Dash forgives you. She's awesome like that.
That was taken from a "rainbro dash" thread. also, dash is adorable.