I feel like a couple of my biggest video game accomplishments were some friggin tough "Vidmaster Challenge" achievements in various Halo games. Most of them were completed with some help of EGA members haha. Each one of these took several hours of intense focus and lots of retries. Here are a few of the hardest:
Vidmaster Challenge: Annual (Halo 3)
After 9/25/08, completed Halo on 4-player Legendary LIVE co-op, with Iron, and everyone in Ghosts.
Only 2.66% of gamers unlocked this
Vidmaster Challenge: Déjà Vu (Halo 3: ODST)
Completed Highway on 4-player Legendary LIVE co-op, with Iron, and no 'Hog or Scorpion.
Only 4.92% of gamers unlocked this
Vidmaster Challenge: Endure (Halo 3: ODST)
In Firefight, on any mission, passed the 4th Set on 4-player Heroic LIVE co-op.
Only 3.84% of gamers unlocked this
Any mission with Iron skull is already tough because any time someone in the party dies, the game sends everyone back to the last checkpoint. It takes a lot of teamwork to make sure that everyone survives it.
The Endure one, I think, was probably the hardest of the three. 4 sets is a lot of sets because I believe there were 6 rounds in each set and they all got progressively harder. There'd be snipers, vehicles, invisible Elites, etc. You're given a limited number of lives. I still think it's pure luck that we got this one.
I believe Mega and Strubes helped out with at least one or two of these and I think SpartanEvolved was with me on all three. What also sucked is that the achievements were not actually worth any achievement points, so there isn't a lot to show for the hours and hours we spent unlocking these haha.