Phineas and Ferb, Season 1

[First lines of the series]

Phineas:
So, Ferb, what do you want to do today? [Ferb shrugs] How about Perry? What does he want to do? [Perry makes a noise] Well, he is a platypus, they don't do much. I, for one, am starting to get bored, and boredom is something of up with which I will not put! The first thing they're going to ask us when we get back to school is "what did we do over summer?" I mean, no school for three months; our lives should be a rollercoaster! And I mean a good rollercoaster, not like that one we rode at the state fair. [a flashback is shown of Phineas and Ferb riding a rollercoaster that consists of one short drop]

State Fair Employee:
Please exit to the left. [flashback ends]

Phineas:
Man, that was lame! Why, if I built a rollercoaster I would... that's it! I know what we're going to do today!

Mom:
Phineas, Ferb, I'm going to go pick up a few things, you boys stay out of trouble, okay?

Phineas:
Okay, Mom. [Mom leaves] We're gonna build a rollercoaster!