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.

Examples of Arms Fair include:

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.
During the Soviet Invasion of Afghanistan the entire Pakistani side of the Afghan-Pakistan border was one big arms fair where weapons from Anyone With A Beef With Russia could be had by the guerrillas. It was also a War Room for The Alliance, a hospital network, and anything else that had to do with giving a Take That to Russia.