Max Payne

Normally you can only throw 1 grenade/molotov, or fire 1 shot of m79, but if you do the following trick you can fire 2 instead of 1. Quickly switch between 2 weapons, let's say you have grenade as main weapon, switch to dual ingram because it's fast and easy to switch, and switch back to grenade. Immediately after you do this, throw the grenade you'll find out that you are throwing 2 instead of 1. This can be done with all weapons but most obvious one are described at the beginning.

Complete the game once through to unlock a cheat mode with "Super Cop," "All Weapons," "Dead on Arrival" mode, "New York Minute" mode, and infinite ammo.

This is how you unlock the Super Cop, Infinite Ammo, and All Weapons cheats. When you unlock them, they can be toggled on and off at the cheats menu.

If you go into Bullettime and throw a grenade, you'll continue to throw grenades until Max is done with the throwing motion. This is assumed that you have more than 1 grenade left ammo wise.

Collect some pain killers within a level, and then choose to quit the game via the menu. When you return to the Main Menu, choose "Continue Game." When you restart the level you'll begin with the same amount of pain killers as you had before quitting. Re-collect the pain killers in that level to augment your supply.