Some of these require an Action Replay, but are so creepy they can still be classified as a glitch. Whenever I find a new glitch that is either useful or cool, I will put it here. I spend most of my time on Pokemon hunting for new glitches so expect more soon.
Always Double Battles This requires an Action Replay and the walk thrue walls cheat activated. First, go into Amity Square with a Happiny. Next, get out of Amity Square without letting the people put Happiny away. Finally, go into any area with wild Pokemon and you will notice the person you teamed up with in Eterna Forest is with you. You will not be able to get rid of her once done, so don't save.
Make The Whole Game A Safari Game This requires an Action Replay with both the walk thrue walls cheat and the one hit KO cheat activated. First, start a new game. Next, go to Rowan's lab (Go thrue trees) and once you go inside Lucas/Dawn should walk you to Rowan. After a bit of talking, you will be asked if you want to nickname your new Pokemon. Now, go back thrue the trees and tell your mom your going on an adventure. All you have to do now is let Lucas/Dawn show you how to catch pokemon and when He/She tries to weaken it Activate the one hit KO and make He/her kill it. Go in any area with wild Pokemon and see what happens!
Easy Big Spheres Underground Bury more than one of the same type of Sphere in the same spot underground, It will combine both of them into one. For example, if you bury a red sphere size 12 with a red sphere size 8 in the same spot and dig them up a second later they will turn into a red sphere size 20.