Whenever a hack writer wants to demonstrate that a person is a conspiracy nut (or just a nut), he has them mention Elvis being alive. This is an immediate tip-off that the writer has no idea what he’s talking about, because those nuts don’t care about Elvis. These same types of writers will similarly try to shorthand “geek” by having the character mention or play Dungeons and Dragons (usually with large plastic models on a gameboard). Again, this reveals the writer’s poor hand, since geeks don’t play Dungeons and Dragons. They pride themselves on not playing it.
Obviously this is an exaggeration and some geeks play Dungeons and Dragons, because if they didn’t, then who is loudly declaiming the adventures of his warrior-thief in the game store right now? But they don’t play without some caveats. For example, no matter how long they’ve been playing or how much of it they’ve seen, they always hate the newest edition, which has always “dumbed down” the game and made it more “roll-play” instead of “role-play”. (Because mere dice are not enough to convey that their dark, haunted character is the most badass half-elf to ever wield dual scimitars.) Whatever the current version of the game is, it’s always a worthless disgrace when compared to either the previous edition (despite the geek initially declaring that edition a travesty) or, more frequently, whatever edition was current when the geek first started playing.
The argument about which previous edition of D&D was best has developed to the point where some claim that tiny vibrations emanating from the fetus that would become Gary Gygax described the quintessential edition of the game, and all others are mere shadows of this Platonic ideal. Rest assured that whatever the best version of D&D may be, it’s not whichever one is being played at the moment.
A lot of geeks pine for the heady days of first edition D&D, but to some, even that is not “old school” enough, and for them there is Hackmaster, which started out as a parody in a gamer comic strip, but now is an actual game. It is “older-school” D&D, or Dungeons and Dragons first edition if it were actually as “kewl” as geeks remember it being.

Every female Vampire character ever. Why yes, she IS a Malkavian!
For other geeks, though, Dungeons and Dragons in any of its incarnations is too juvenile, and they prefer the more mature and sophisticated games of White Wolf, where they can pretend to be crazy vampires having gang wars. This system is referred to as the “Storyteller” system, which demonstrates why their games are so much more intricate than mere D&D could ever hope to be. After all, they are “telling stories” whereas D&D people are merely “playing a role”. They are crafting intricate and intellectual narratives and not just pretending to be superhuman beings fighting others for valuable prizes.
One advantage that Storyteller fans will never tire of telling you about is how their system doesn’t have “alignment”, which in D&D describes a character as Good or Evil. This means they are more free to explore the various shades of morality and motivation, even though everyone just plays their characters as sociopaths anyway.
The other major competitor against D&D is GURPS, which is a generic system. In theory this means that you can use the same rules to play a game about spies, space marines, Elizabethan nobility, cavemen, or sentient bees, thus putting no limits whatsoever on your gaming. The truth, however, is that even GURPS players hate the rules for GURPS and the sourcebooks for all these different possibilities offer little more than, “If you’re going to play as sentient bees, don’t forget to have beehives!” because it’s worth forty dollars to have a hardback book tell you that (not that anyone who buys any of the sourcebooks ever plays those settings anyway).
In addition to other third-string games like Shadowrun (which asks the question of how many cliches can be crammed into a single RPG) and Rifts (which makes Shadowrun seem like a Ph.D thesis) there are plenty of “rules-light” RPGs which again emphasize “shared narrative” over die-rolling and stats-comparing. Only geeks are willing to buy a rulebook on how to play “let’s pretend”.
What these games all have in common is this: they’re NOT Dungeons and Dragons. Because that’s what LOSERS play. Well, losers play a different version than what the geek plays. Well, they play the same version but without the awesome house rules that he plays. Well…look, quit arguing and listen to this awesome story of how I tricked Orcus into giving me his wand!
Playing D&D is the one cliche that geeks seem to wish to avoid, so geeks LOVE not playing Dungeons and Dragons!