Resident Evil 4

Alternate Handcannon
Complete the game twice.
(Thanks to Tcools04@yahoo.com)

Assignment Ada and Mercenaries Mini-Games and Professional Difficulty
Complete the main game once.
(Thanks to anditendedwithe@hotmail.com)

Double the Broken Butterfly Ammo
The guy will not sell you this gun if you found it, however, if you buy it first, you can hold twice the ammo.
(Thanks to anditendedwithe@hotmail.com)

Free Ammo
Upgrade any weapon's capacity with a merchant and he will refill the magazine free of charge. Upgrade the magnum and TMP to get this too.
(Thanks to anditendedwithe@hotmail.com)

Handcannon
Get a five-star rank on all mercenaries.
(Thanks to anditendedwithe@hotmail.com)

Infinite Rocket Launcher and Mathilda Handgun
Beat the game.
(Thanks to anditendedwithe@hotmail.com)

Punisher Pistol
Complete the quest for the merchant who sells you upgrades for your weapons. Search two areas of the game for the 15 blue medallions, and shoot them.
(Thanks to anditendedwithe@hotmail.com)

Raise Max Health
Mix GREEN HERB + RED HERB + YELLOW HERB.
(Thanks to anditendedwithe@hotmail.com)

Unlimited Ammo for Handcannon
Fully upgrade the Handcannon's firepower, reload, and capacity. The 'exclusive' option then raises the attack power to 99.9 and gives infinite ammo.
(Thanks to anditendedwithe@hotmail.com)

Unlock Ada Wong
Score 4000 or more on Game Type A. Alternately, hit all of the targets on Game Type A.
(Thanks to Sam)

Unlock Ada Wong for use in The Mercenaries
Get a four-star rating in the Pueblo map of The Mercenaries.
(Thanks to anditendedwithe@hotmail.com)

Unlock Albert Wesker for use in The Mercenaries
Get a four-star rating in the Waterworld map of The Mercenaries.
(Thanks to anditendedwithe@hotmail.com)

Unlock Ashley Graham
Score 3000 or more on Game Type A.
(Thanks to Sam)

Unlock Bella Sisters
Score 4000 or more on Game Type B. Alternately, hit all of the targets on Game Type B.
(Thanks to Sam)

Unlock Broken Butterfly
Return to the locked door in the hall south of the hedge maze with Ashley. If you piggy-back with her, she will unlock the door.
(Thanks to anditendedwithe@hotmail.com)

Unlock Chicago Typewriter
Finish the mini-game, Assignment Ada.
(Thanks to anditendedwithe@hotmail.com)

Unlock Don Diego
Score 3000 or more on Game Type B.
(Thanks to Sam)

Unlock Don Esteban
Score 3000 or more on Game Type B.
(Thanks to REFan)

Unlock Don Jose
Score 3000 or more on Game Type B.
(Thanks to Sam)

Unlock Don Manuel
Score 3000 or more on Game Type B.
(Thanks to Sam)

Unlock Don Pedro
Score 4000 or more on Game Type C. Alternately, hit all of the targets on Game Type C.
(Thanks to REFan)

Unlock Dr Salvador
Score 3000 or more on Game Type B.
(Thanks to Sam)

Unlock Hunk for use in The Mercenaries
Get a four-star rating in the Island Commando Base map of The Mercenaries.
(Thanks to anditendedwithe@hotmail.com)

Unlock Isabel
Score 3000 or more on Game Type D.
(Thanks to REFan)

Unlock Jack Krauser for use in The Mercenaries
Get a four-star rating in the Castle map of The Mercenaries.
(Thanks to anditendedwithe@hotmail.com)

Unlock JJ
Score 4000 or more on Game D. Alternately, hit all targest in Game D, except Ashley.
(Thanks to REFan)

Unlock Leader Zealot
Score 3000 or more on Game Type C.
(Thanks to REFan)

Unlock Leon with Handgun, Rocket Launcher and Shotgun
Score 3000 or more on Game Type A.
(Thanks to REFan)

Unlock Luis Sera
Score 3000 or more on Game Type A.
(Thanks to REFan)

Unlock Maria
Score 3000 or more on Game Type D.
(Thanks to REFan)

Unlock Merchant
Score 3000 or more on Game Type C.
(Thanks to REFan)

Unlock Soldier with Dynamite, Hammer and Stun Rod
Score 3000 or more on Game Type D.
(Thanks to REFan)

Unlock Zealot with Blowgun, Scythe and Shield
Score 3000 or more on Game Type C.
(Thanks to REFan)