Timmy: Likes big fat effects, stuff that makes people go Holy




!!! when it hits the board. They usually love "fatties" or "beatsticks", highly costed yet strong creatures. I'm guessing Timmy would be the guy who likes to get really silly effects in one impressive area and be the best at it. He's the guy with the twinked out charger, sneak attacker, just about anything that can hit for a ton of damage. As a Dungeons and Dragons player he'd like respect for being very strong in one area. Some decks that come to mind are Secret Force, Fires, The Claw, etc.
Johny: This is M:TG code for somebody who wants to win about half his matches, but winning isn't the big thing for him. He plays wacky theme decks and trys to do cool things like mill somebody out with a clunky combo or do silly mechanical things to win in an unexpected fashion. "Johnny" cards are things like The Cheese Stands Alone, Enduring Renewal, Squirrel Nest with Earthcraft, Worldgorger Dragon, that sort of thing. So this could be somebody who plays against character, does odd class and equipment combos, who really customizes his character.
Spike: This is the guy who doesn't really care how he wins, just that he does. This person will play the strongest decks(builds) and cards(feats, spells, equipment). This term is also used for people who take Magic "seriously", tourney players, registered people, people who are conversant enough with the rules to judge, etc.
In roleplaying terms a Spike would be someone who is very mechanically strong, too.
These aren't all or nothing. For instance, a Spike/Timmy would be someone who would try to play the strongest decks as best as he could...
But he would beat your ass down with Akroma and flashy bombs.