I'm not talking about the cheapest bosses or the stupidest scenarios. 

I'm mainly talking about the cheapest ways YOU've beaten bosses / entire segments of a game...intentional or not. 

I'm really curious how often people just go with "Fuck it! This works, I'm doing this for the next 500 fights."

https://www.youtube.com/watch?v=1XoGW4I9T28

I'm so ashamed

https://www.youtube.com/watch?v=m80dr7Q_-ZU

Using the Spark ability on every True Arena in Kirby games.

i sat on a rock in the desert and killed deathclaws with a fuckn broken pistol... stupid fallout nv, the shortcut is so broken, you get to a good level realy fast.

Monado Busta

https://www.youtube.com/watch?v=WbZik0IA9DM&feature=youtu.be

After enough frustration.

Dark Souls: beating a boss without entering the boss room

Cheapest trick I've ever seen (and did lol)

https://www.youtube.com/watch?v=BdlCr7MEud0

Probably shooting the Drake's tail in Dark Souls.

I honestly feel like that had to be intended. By the time you'd be strong enough to beat the Drake and take the tail in legitimate combat, the sword would be worthless due to its expensive and overall poor upgrades.

As for me, I have another Dark Souls related one. Dark Souls 2, to be exact. The Dragonrider trick. It is so cheap, but such easy souls, especially if you want to abuse some bonfire ascetics. https://www.youtube.com/watch?v=44J5XWJ7q7U