I used to play Yu-gi-oh and i had LOTS of cards and i had a really really really powerful dragon which was like really overpowered, people were offering me 100's of cards to trade him XD
Yu-Gi-Oh!, Magic: The Gathering, and Poke'mon, are what I tended to play even remotely seriously. With Yu-Gi-Oh! I had a Toon World deck, a Blue-Eyes White Dragon deck, and a Fusion-based deck. None of them were to be taken seriously, they were mostly for fun, but every now and then I'd get a win. With Magic: The Gathering, I'd run a Blue/Black deck. I'd force constant discards, and inflict petty damage, all the while preparing to attack. While I'm not championship material, I'm confident enough I could give anyone a run for their money. With Poke'mon, I had a Grass/Psychic deck. Nothing fancy, I'd just evolve, then attack.
I used to play Chaotic. (Also had a show on 4kids. It stopped in the middle of season 3 for no reason. Even though they had announced plans for 7 seasons after season 2)
Yes none of my Yugioh decks are too be taken seriously, I can definitely build a great one if I wanted to.
I throw down pretty hard with magic the gathering. I could talk all the jargon but I doubt anyone but a player would have any idea what I'm saying.
I love Yugioh! I run a psychic gusto deck, and I'm so frustrated because I can't find someone to play against so I can test it out! I used to run a Naturia, which is a surprisingly good lockdown deck if you use it properly (I only got to use it a couple of times, but it never lost).
I had a great deck of pokemon cards 2 years or so ago, but I lost interest in them and gave them all to my friends brother, I regret it now because my best card is now a porygon xD
I know how to play Yu-Gi-Oh and Pokemon, but I haven't played either in years... I have god-siblings who play Magic The Gathering, but I don't know how.