What was the hardest mission in the series?

We all know GTA games aren't easy. Sometime they can be quite hard, even frustating. And sometime there is that mission, that freaking mission that no matter what, we can't beat - only after a lot of rage quits and an almost broken controller.
For example the various driving school in GTA San Andreas were pretty hard, but nothing will even be compared to that one mission.
THAT ONE FREAKING MISSION.
You all know what I'm talking about: all we had to do was follow the damn train!

Haha, I remember the train mission. Don't worry, I failed it so many times

Out of every GTA game which mission was the hardest? I think the flight school in the GTA San Andreas. Who the hell made that thing and why? It's like they wanted us to suffer a bit. I am already horrible when it comes to controlling ANY planes or helicopters but hey, let's put a flight school in the game. That should be fun.

It took me such a long time to complete all of it... those damn circles that you had to fly through? I always missed one or flew in the wrong direction.

The worst part about the flight school missions is that (most of them, or all of them? Don't remember) were mandatory for the story. I struggled a lot...
Speaking about flying, that mission with the toy plane was also a total pain.

If we are talking about every game in the GTA series, the hardest mission for me was in GTA Vice City. It was a mission where you had to fly that little helicopter, pick up the bombs and take them to each floor of a building on that construction site. I remember even deleting the game from my PC once, beacuse I was so fustrated with this mission. When I calmed down, after a couple of days, I installed the game again and passed the mission on the first try :sunglasses:.