Beating any of the Destiny raids.  

Exploring the map of final fantasy the cystal bearers
I also remember having nightmares because of Medievil game altough thats the opposite subject of this thread  

i think i wrote godswar story on this forum at least 10 times. so im gonna talk about pocket legends.

i discovered that game way back in 2010 through my sister's ipod. i downloaded it in late 2011 on my own device then I found their newest release called Dark Legends. I got famous there, had good stat, good guild, part of the Korean comm, I was one of top PvP, CTF ranker with epic gears and mastered all the skill tree+combos. I quit it when before Lv26 cap patch came out.

Later in 2012, I played their newest release Arcane Legends. I knew what to do(dungeon grinding), so I made dungeon solo run vids. I instantly became famous and got over 100k views total with only 6 videos. I had over 100+ friend requests EVERYDAY. Also I got all the end-game gears for Lv16. So I got bored and quit.
My videos LATER became an issue. Because They BUFFED the dungeons I used to farm, so it was impossible for Lv16 to SOLO them. On top of that I was Sorcerer, so can't tank those monsters ever. Over the course of time while I was playing Graal it got many dislikes and comments saying I was a hacker. So I just deleted all the videos since I didn't care about those games anymore.

2015 Incident Graal to Dark Legends:
I had a Dark Legends rare 'event' item, it became super rare($40 worth) then I got scammed by an iClassic player. Which I got him banned for an year on iClassic. Yog knows his DL username, but he ain't telling me? If I knew his username, he could've been banned for permanently since I used to be in AoA.  

Probably the first time I ever beat the Elite 4 in Pokemon Emerald.

I was so new to Pokemon when I did that, it honestly felt like the hardest thing I had ever done in a video game.

Up until I beat them again like 3 days later.

I've also had my fair share of pretty intense moments while playing Destiny PVP and CS:GO with my friends.  

Spyro the Dragon: Ripto's Rage
Whenever my brother, sister, or I played the level Sunny Beach, the three of us would bet on which baby turtle would make it to the very end of the level (by the portal back to Summer Forest) first.
Since there were 3 of us and 3 turtles, it worked out pretty well lol.

****
Also the first time I played Simpsons: Hit & Run, I crashed my car into a streetlight in front of the Kwik E Mart cause I had to go inside as part of my mission. My dad and I thought that was pretty funny  

Beating "tubular" in super Mario world.