Game Cheats:
Rocket Town Materia Quest:
Enter OK, Switch, Cancel, Cancel while in the rocket to get huge Materia.
View ALL Cutscenes:
If you go to the (~:Program FilesFinal Fantasy VIImovies) folder you will be able to view ALL of the in-game FMVs.
Boss battles - easy victory:
Airbuster (fought outside No. 5 Reactor after a brief meeting with President Shinra) - Enter the battle with Cloud and Barret's limit gauges full. When the Airbuster is facing away from one of them, have them use their limit break. From behind, Braver and Big Shot cause over 600 points of damage each to the Airbuster. The combined power of the two can destroy the Airbuster, which has about 1200 HP, in two hits, provided he is facing away from whoever uses the limit break.
Gi Nattack (fought in Cave of the Gi) - This one's easy. If you have an X-Potion, use it on the Gi Nattack and it will kill him. If you don't have an X-Potion, five or so Cure 2 spells should be enough to take away his 5500 HP.
Cosmo Canyon - Back Room:
After Meteor has been summoned, return to Cosmo Canyon and visit the Item Store (to reach it, climb up the ladder to the far right outside on ground level). There was previously a rope barring a path that lead around to the back of the store, but now that it's disappeared, follow the path around. You'll find yourself in a room with the "Fullcure" materia and two other items.
If you don't find Cure 3 or White Wind effective enough, you might like to use Fullcure.
Powerful weapons to Steal early on:
Early on in the game you can steal powerful weapons that cannot be bought until you reach Junon for the first time. They are the best you can find at that point in the game.
Striking Staff (Aeris) - Steal from Eligor (creature that appears to be riding some sort of chariot) that appears in the Train Graveyard.
Hardedge (Cloud) - Steal from SOLDIER 3RD (sword wielding enemies) that appear on the 67th Floor of the Shinra Building.
Atomic Scissors (Barret) - Steal from Custom Sweeper (large robot similar to the ones you fought in the No.1 Reactor) that appear outside Midgar in the Midgar Area of the world map.
Grand Glove (Tifa) - Steal from the creature in the Mythril Mines that is wielding a ball and chain (sorry, but the name of the creature escapes me).
As for Red XIII's and Yuffie's, I'll submit them when I find them, if there are any.
Final Fantasy VII cheats:
Ancient Forest before Disc 3:
Ride up the hill with a black, gold or green chocobo.
Restore Energy during Chocobo Races:
Hold 'Pg Dn' + (Target) while racing a Chocobo.