Yu-Gi-Oh! Legacy of the Duelist

Requires you to finish every duel in the Yu Gi Oh GX campaign (not including reverse duels),

This can be achieved either by playing with the story deck provided or your own user deck (user deck recommended as in campaign you can use forbidden and limited cards).
I'd also recommend using a variation of the "cheating Exodia" deck unlocked in Yu Gi Oh (Duel Monsters)

Heres what i used:

Blue Medicine [x1]
Cup of Ace [x1]
Dark Hole [x2]
Dark World Dealings [x1]
Earthquake [x1]
Fissure [x1]
Goblin's Secret Remedy [x1]
Gold Sarcophagus [x1]
Graceful Charity [x3]
Heart Of The Underdog [x1]
Magical Stone Excavation [x1]
Pot Of Duality [x3]
Pot Of Greed [x3]
Raigeki [x1]
Swords Of Revealing Light [x3}
No Entry [x2]
Raigeki Break [x3]
Torrential Tribute [x1]
Wall Of Revealing Light [x1]
Battle Footballer [x3]
All five pieces of Exodia (Left arm, Right arm, Left leg, Right leg, Exodia the forbidden one)

Just focus on getting all 5 Exodia cards in your hands whilst stopping the enemy from attacking and you'll win matches very quickly! Same with the other campaigns!