Slope glitch:
This bug is used to just walk over slopes that normally would do a animation and push you down the slope. If you hit pause at just the right time you can pause the animation and walk over the slope. The timing for the animation cancel is very precise so I just spammed and walked even over a row of slopes. The place where I found this very useful was in the flying type gym in Hoenn. I posted a screenshot of how it looks when its pulled of.
Login Visual Bug:
I think this is a very common bug that happens when I go into an encounter and logout to go to the Pokecentar. But if you log back in very quickly there is a chanse that a visual bug will happen where you are not in the Pokecentar but all the npcs are there and you cant move till you logout and log back in (Im still not sure why this happens and my method of re-loging back very quickly dosent work 100% of the time and it might have to do something with my bad internet connection). I also posted a screenshot of this glitch when it dose happen.
Hope this helps