What's the hardest game you've ever played

I don't mean hard because of broken controls or just a bad game.

I mean just, plain, brutally hard. The game that taxed your gaming prowess to its limits.

Games where you needed the responses and reflexes of an android to get through.

Games that you could die by blinking at the wrong time.

Which game had you throwing the controller across the room?

I'm sure I have many but the one that instantly came to mind was Gradius on Playstation 2.

This game literally had me throwing the controller in fits of rage. It was the first time I had done that in years, and I honestly don't think I've done it since.

Viciouslly hard games tend to fall into 2 categories:

1. The kind where you put you whole life on hold (school, work, friends) and devote yourself fully to beating this game.

2. The kind where you say "F" this game, walk away and never think or speak of it again.

Which games were your toughest?