In the Cheats Menu, enter:

Black, White, Black, White, Left Trigger, Right Trigger, Start

Go under Extras into the Cheats-Menu and enter following keys.

Fully Loaded (Unlimited Ammo): White, Black, Y, Black, A, White, Start

Bulletproof (Infinite Health): Left Trigger, Right Trigger, Y, Y, Right Trigger, Y, Start

Adrenaline Rush (Infinite Adrenaline): A, Left Trigger, Y, A, Left Trigger, A, Start

Magic Bullet (One Shot Kills): Right Trigger, Black, Y, A, Right Trigger, A, Start

Battering Ram (Instant Crash): Black, Black, A, A, Y, White, Start

Time Out (Infinite Timer): Right Trigger, Right Trigger, White, Y, A, Black, Start

In the Cheats Menu, enter:

Unlock Art Gallery: Y, A, Black, White, Y, A, Start

Unlock Movie Gallery: Left Trigger, Left Trigger, Y, A, Left Trigger, Right Trigger, Start

Battering Ram: Win with the Professional ranking.

Bulletproof: Win with the Professional ranking.

Fully Loaded: Win with the Psychopath ranking.

Time Out: Win the Career Criminal ranking.