A deck with no structure just has really good cards. I've seen these decks tear the field up... and then ive seen others based on this that totally sucked.

A deck based on a theme is like a Chaos, Archfiend, Dark Scorpion, Deck Depletion, Burn, Destruction, stuff like that.

A deck based on a Type is a deck based on Dragon, Fiend, Beast, Pyro, Warror, and all those.

A deck based on a Attribute is a deck based on Dark, Light, Fire, Water, Earth, or Wind


I have to go with a Themed deck.

actually they are all equally as powerful...so I am not voting here