Arms Fair

Basically, a yard sale for helicopter gunships, tanks, artillery, large quantities of automatic weapons, and other useful tools for starting and finishing small wars.

Coming in two forms:
 * Legal: Organised by a government or big corporation and taking place in a conference centre. Attract protestors.
 * Illegal: By a crime gang or terrorist group, located in some field somewhere. Attract police and military.

While it has almost certainly occured in fiction, having a Hood Ornament Hottie in skimpy camo holding a large machine gun sounds too much like self parody for any real company to actually do it, regardless of what occurs at E3.

Anime & Manga

 * A short for Gundam SEED Astray shows Lowe and the gang at a fair on Earth and getting in trouble after he buys the head of a BuCue containing sensitive military information.

Film

 * Black Hawk Down features extensive sequences showing off that the entire city Mogadishu qualifies as an Arms Fair, despite being under the control of a ruthless warlord who will kill people trying to get the food supplies sent by various aid groups.
 * In the Pre Titles Sequence of Tomorrow Never Dies, James Bond must infiltrate an Arms Fair to confirm its location and allow a Tomahawk missile to take it out. As the missile is launched, he discovers an L-39 Albatros with nuclear torpedoes on board...
 * Lord of War has had several - all illegal. And with Russian-Military-themed women dancing on tanks.
 * The one with the Russian-Military-themed women was implied to be legit, or as legit as you can get with an arms sale held by corrupt elements of the post-Soviet military hosted by a laissez-faire Middle Eastern state.
 * The plot of Deal Of The Century revolves around one.

Live Action TV

 * Airwolf had mini-ones.
 * Chuck has "Weap Con," of which Casey was an enthusiastic attendant every year.

Video Games

 * Goldeneye for the Wii features a level taking place at an arms fair.

Real Life

 * DSEi, held every year in London.
 * Similarly, small gun shows held in various places all over America.
 * The Gun Markets of Pakistan from Vice TV
 * After the collapse of the Soviet Union, just about anything military was up for sale from KGB badges to mothballed fighter planes.
 * The Highland Games(a Scottish ethnic festival held in several places including Portland Or), in a surprising downplayed version. There are stands for collector's swords some of whom could actually be used in combat by someone who knows how.