Unlock all levels in classic mode, then clear all the gaps in all fifteen levels. All the cheat options will now appear in the cheats menu on the game options screen, and can be turned on or off.
Unlock Natas Kaupas:
Enter oldskool as a password.

Unlock Nigel Beaverhausen:
Enter sellout as a password.

Unlock Paulie:
Enter 4-wheeler as a password.

Infinite Rail Balance:
Enter straightedge as a password.

Unlock more characters:
Enter costars as a password.

Always Special:
Enter likepaulie as a password.

Unlock Phil Margera:
Enter aprilsman as a password.

Level Select:
Enter d3struct as a password.

Unlock all movies:
Enter boxoffice as a password.

Unlockable: Characters
Complete Boston Story Mode: Ben Franklin
Complete Barcelona Story Mode: Bull Fighter
Complete Berlin in Story: Graffiti Tagger
Complete classic mode on sick: Jesse James
Complete New Orleans in Story: Jester
Complete classic mode on Sick: Natas Kaupas
Complete Story on Sick: Nigel
Complete Story on Normal: Paulie
Complete Story on Easy: Pedestrian Group A
Complete Story on Normal: Pedestrian Group B
Complete Story on Sick: Pedestrian Group C
Complete Classic Mode on Normal: Pedestrian Group D
Complete Classic Mode on Sick: Pedestrian Group E
Complete Story with 100%: Pedestrian Group F
Complete Classic Mode with 100%: Pedestrian Group G
Complete Story on Easy: Phil Margera
Complete Story: Pro Skater Level
Complete Skatopia in Story: Ryan Sheckler
Complete Australia in story mode: Shrimp Vendor
Complete classic mode on Normal: Steve-O
Complete story mode on Normal: The Hand
Complete classic mode on Normal: Original Tony Hawk