My most prized card came to me under no special circumstances. I merely bought a booster pack and he was my holo. However, I had always wanted one and when I pulled him, I was ecstatic. I played him every duel I got the chance to, and often brought me the win as a total finisher. Over time he declined and I was forced to retire him. His battered visage can still be seen within my collection book, waiting for his time to rise again. This card means so much to me that even when I pulled a brand new duplicate out of a pack, I traded it away so there wouldn't be the risk of confusing the two. This card is the only Duel Masters Card on this thread to my understanding. The fiercesome and proud Deathliger, Lion of Chaos.
Deathliger, Lion of Chaos
Demon Command, 7 mana
mana number:1
9000 power
Double Breaker
For those who aren't Duel Masters savy.