Getting a college roommate is random chance.
Sometimes you get lucky, and sometimes you get a pony.

Rainbow Dash enrolls at an Earth university.

Update: and then some other stuff happens.

[Second-person romance fic starring "you" and Lyra] Months have passed since you, a human, have appeared in Equestria and were taken in by a pony by the name of Lyra Heartstrings. Now, you and her are the best of friends, being nearly inseparable.

But what happens when you begin to develop more romantic feelings for the musical mare? Will you face rejection and ridicule? Or does Lyra have some secret feelings of her own?

NEW! Internet Reading!

A thousand years is quite the generation gap, so Princess Luna decides she has to get with the times. However, this isn't quite as easy as she thinks it will be...

Twilight finds a dusty old book full of puns and begins to use them, much to the dismay of her friends, considering her puns are slowing down their travels and they need to be PUNCTUAL.

Twilight gets a distressing letter from Celestia and rushes to Canterlot.
What happened to the princess? What is Luna up to? Why do I sound like the narrator to a bad crime drama?
The first chapter is inspired by a drawing from JohnJoseco. The rest will be my own madness doing its part.

A story of how two ponies, both opposites in personality, formed a bond of friendship and love that lasted throughout an entire lifetime...

It's Pinkie's first day as a Pokemon trainer! After she selects her Pokemon from professor Sparkle, she's ready to take on the world!

Pinkie Pie learns a new word that starts with 'F' and ends with 'K'. No, it's not firetruck.

How will she use this new word? Let's find out.

One by one, Twilight and her friends must come to terms with the consequences of being the Elements of Harmony.

These stories take place in the intervening time between Season One and Season Two,
with the exception of Ditzy Doo: Muffins, which takes place early in Season One.

The series continues in the sequel, Secrets and Lies.

Pony Psychology has a TV Tropes Page.

Twilight Sparkle and her fellow Elements of Harmony have faced down supernatural foes of the highest order, but sometimes the deadliest danger can come from places one would least expect. As Twilight is forced to bear a devastating secret, her efforts to keep the Elements together may well tear them all apart.
The plotline of the thrilling Pony Psychology Series continues with an exploration of deception, despair and Discord.
This series takes place between Season Two and Season Three.
Secrets and Lies shares the Pony Psychology Series TVTropes page.