Most frustrating game levels/moments/anythings?

Post frustrating video-game levels, moments, parts, anything.
For me, the most frustrating video game level, has to be either Ridley's second fight from Super Metroid, and Quickman's stage from Megaman 2.
Quickman's stage is pretty obvious. It's just a pain in the neck, just because of the lack of checkpoints, and the LASERS!! 
Now, i'll talk about Ridley.
The only way i beat Ridley on his second fight was with Game Genie.
Either i'm really terrible at SM, or he's really, really hard to beat.
Seriously, he keeps using his tail as a pogo-stick, and you fight him at a small area with lava around it, and he keeps grabbing you when you are in the morph ball, and he keeps shooting fire at you, and if you aren't wearing the Gravity suit, you'll probably die in less than 15 seconds.
I know Super Metroid was suspossed to be challenging with all the puzzles, hidden stuff, and the bosses, Maridia, and all that, but for me, Ridley's second fight is too much.

So, in your opinion, what is/are the most frustrating video game moment(s), level(s), that you have saw?