Actually, I guess I’ll give one I discovered too…
In Baldur’s Gate the final battle has you attacking Bhaal and a couple of his henchmen. You appear at one end of a large room (with an obstacle of some kind in the middle). Bhaal and company are on a raised platform on the other end of the room.
The catch was that the baddies wouldn’t move until they actually saw you and their sight distance was the same as yours. So, I would send one character with as many fireball type spells and effects as I could around the center obstacle until the edge of the platform that Bhaal and company just came into view. I then started launching all of my fireballs at the corner of that platform. The burst radius of the explosions would start damaging the baddies (and the combat display would show them taking damage) but they never moved or retaliated unless they could actually see you! I was usually able to take out everyone but Bhaal himself that way.
I would then let Bhaal see that one character. He charged towards where the character was, but before he got there I threw an animal summon on that point. He stopped to take out the animals and my entire party unloaded on him with missile weapons and other non-area attacks until he went down.
Net result was that I could finish off the entire final battle and none of my characters ever took a single point of damage.
Then there was the way to start Baldurs Gate II with all of your equipment from the previous game.
You can import your characters from the first game into the second, but the very first thing that happens to you is that you get captured, taken prisoner and all your equipment is taken from you. Then there is a cutscene where you are tortured for a while.
The catch here is that the cutscene was actually in the game engine with the interface toggled off. Which means you had access to all game functions, even if it wasn’t obvious.
So, you would start a new game and import your character from the first game. When the game starts the screen first turns black (and you hear yourself getting knocked out). If you immediately hit the pause button as soon as the screen went black, you could pause the game before you were knocked out. You couldn’t see anything but you didn’t need too.
If you toggled the interface back on at this point you could open your inventory and see that you still had all of your imported items. Simply remove them and drop them, then unpause the game and allow the cutscene to complete. Then, as your first action, pick up all of your equipment that is now lying on the floor of your cell.
Made the first few chapters of the game very easy…

