1 hit Gator kill:

Here's a secret trick to kill the Gator boss. When he starts advancing on you, you will notice a yellow light on the left wall. Push the X button and a canister will fall to the ground. When the Gator chomps down on the gas canister, shoot the canister and the Gator will blow into bloody chunks!

Infinite Submachine Gun:

Beat either alternate scenario with an A or B ranking without using any health sprays

Infinite Gatling Gun:

Beat either alternate scenario with an A or B ranking without saving.

Infinite Rocket Launcher:

Beat either regular scenario with an A or B ranking.

Play as Hunk:

Beat the regular and alternate scenarios with either character and get an A rank. Then you will get the option to save to a normal character with infinite weapons, or another scenario. Pick another scenario and you will start a quest with a character named Hunk. He is an Umbrella SWAT soldier who has his own problems.

Play as Tofu:

This one might take a while. Play all 5 possible scenarios (Leon 1 and 2, Claire 1 and 2, Hunk). Now save and you will start a new game with a new character. His name is Tofu and he's, well, a big piece of tofu. However, you can only use a knife with him (and why zombies would want to eat tofu is beyond us.)

Change your clothes:

Start a new game on the 1st scenario with either Character on Normal difficulty. From the beginning until you reach the gate to the courtyard of the police department; do not pick up one single item. This will generate a new zombie under the lower stairs around the police department. This new zombie is actually Brad Vickers from Resident Evil 1 (the chopper pilot). After you kill him, push the action button to grab the special key. Now go into the police department and go into the west wing save (the darkroom) and you will see two lockers. Use the key, and you will have new outfits!

Picture of Rebecca:

In the S.T.A.R.S. room, move to the far desk and examine it. It should state something like, "The desk is a mess, looks like someone was looking for something." If you examine the desk 50 times, a roll of film appears. Go down to the dark room and develop it to discover a picture of Rebecca (from the first RE) in a basketball uniform.

Shoot your TV:

Take the east exit out of the basement and go to the area with the two demon dogs and a manhole. When the two dogs are dead, have your back facing the manhole and walk forward until the camera view changes. Arm your shotgun and shoot until bullet holes are on your TV screen.

Mixing Herb Power-Ups:

The herb power-ups can be mixed using the "combine" command for varying, but very beneficial results. This will also save storage space for holding puzzle items. Here is a listing of some herbal combinations and the outcomes:

1 green herb + 1 green herb = Full health recovery.
1 green herb + 1 blue herb = 20% health recovery and antidote.
1 green herb + 1 red herb = Full health recovery.
1 green herb + 1 red herb + 1 blue herb (in that order) = Cure-all (full health recovery and antidote).
3 green herbs combined = Full health and more.