The weapons and extra ammo cheat fills out your guns and ammo, giving you all the weapons in the game and topping off your bullets. Handy if you're high up with out one and want to get down quickly and safely. The GTA 5 Give Parachute cheat does exactly what you it sounds like, and gives you a parachute.
Michael's Bullet Time ability slows time around him and Trevor has Red Mist, which decreases the damage he takes, and boosts the damage he inflicts on enemies.
Franklin has Driving Focus to slow down time when you're in a car. This special ability cheat will refill the special ability meter for whichever GTA 5 character you're playing.
(Image credit: Rockstar Games) Special ability refill