Quake is the most difficult game I ever tried. Of course this was in multiplayer 5-6 years ago. I was playing quake a lot with my friends and really good at it, so I thought. Untill we arrived at a huge LAN party (500+, at least that is a lot when you are only 14) and I signed up for the Quake competition.

I lost -5 (he kept shooting me in the magma with the rocket launcher) 53 or something.

Now that was a challenge, the hardest ever

note: the guy who beat me (in my first game) won the competition