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Blue Eyes Arts
Red Eyes Arts
Dark Magician Arts
Summoned Skull Arts
All the Gaias

Misprints.

Playable ones, though.

I had to think on this one, but the top of my list would be the three misprints I have to be:

Counter Counter [1st Ed.] No Counter Trap icon
Elemental Hero Wildedge [1st Ed.] Listing Elemental Hero Edgeman as a Fusion Material monster.
Ocean Dragon Lord - Neo Daedalus [1st Ed.] Missing it's special summoning condition.

Next would be the TLM Chaos Emperor Dragon - Envoy of the End, with the mispelled "your" in the effect text. Even though I wish they had made a non-Envoy version of this card.

My Black Luster Soldier - Envoy of the Beginning.
This card has been special to me, unlike its counterpart I don't have a dozen of these and seen very few of them, aside from the one I own, I had traded some kid for it, and within 10 minutes the little b*****d managed to snatch it back without my knowing. I forget what I traded for it.

I really liked watching Black Luster Soldier in the show and hadn't been too surprised to find out in GX that Yugi had it, considering Kaiba had the other one. Though I don't recall Yugi ever using this card. I even remember the episode in GX when the Sacred Beasts were summoned, one of the card singles' pictured in the glass case was this card.

The rest of my list are various sets like Warrior of Zera and the Fiend version, have yet to get the Fairy one. Some of the "Jar" monsters. [Cyber Jar, Morphing Jar, Dimension Jar, Dice Jar]

I have a riryoku field trap with 3 l's in spell, like "cancels a spelll card

also gather your mind. almost useless unless you have 2 and want your deck shuffled, but i like the art.

EDIT- oh yeah, and shiny gilford the lightning.

archfiend of gilfer i use and wouldn't trade for.

Misprints

"Preprints", cards that were made then remade to match something (Two-mouthed dark ruler)

Destiny Hero - Double Dude (I have no idea why, I have six of it though)

Self-destruct button -.- just to piss people off, it does help in decks like Six Samurai (Backs to the Wall + S-DB= Awesome) I have "saved" myself in so many duels with that.

Screw ups, and not like misprints, I mean when a card's shininess is weird, like the Wildheart with secret rare writing, ultra rare picture, or, my favorite, my chain dog with the top is rigid on top (Hard to explain)

I have an original MFC Ultra Rare Dark Paladin. Love that card.
Also a super rare LOB Mystical Elf.
Spanish Ultra Leg of Exodia. Don't know if its the left or right, cause it's in spanish.
I have a misprint Base rare Princess of Tsurgi. There is an extra border on top, and the border is missing on the bottom.
Ultra rare Marauding Captain, Ultra rare Gemini Elf.
Original MRL Ultra Rare MST, and Super Rare MRL Giant Trunade.
My favorite though out of all my shiny cards would be my alternate art Polymerization.

Ah. Then it would be the Left leg.