Last Plan Standing

A Gambit Pileup has ensued, and the dust finally settles. Someone emerges, triumphant. The winner may have been one of the major Chess Masters (or even one Chessmaster playing the others off each other), but it's just as likely that it's a relatively minor player, the Spanner in the Works or even Those Two Guys. If the Gambit Pileup has been particularly bloody, the victor might win by simple virtue of being the last one standing--perhaps Atop a Mountain of Corpses.

In some cases, the winner doesn't even have a plan--they were in the right place at the right time, and in a prime position for victory.

Live Action TV

 * On Lost when the dust finally settles after all the years of scheming and back stabbing between Jack, Locke, Ben, Widmore, Jacob and the Smoke Monster it is kind hearted Hurley who comes to rule the island.

Literature

 * Simon at the end of Tad Williams' Memory, Sorrow, and Thorn trilogy is at least a partial example.
 * It sometimes seems that Daenerys is being set up to be this at the end of A Song of Ice and Fire, but that's speculation.

Theatre

 * Fortinbras in Hamlet is established as seeking revenge on Denmark for past grievances. He ends up having the crown fall into his lap because all the legitimate claimants have killed each other.

Video Games

 * Liquid Snake at the end of Metal Gear Solid 2. His only real involvement with the plan was getting Solid Snake involved so that he was able to be released. However, the enormous circle of backstabbing between Dead Cell, Solidus, Olga and Ocelot cancelled them out to the point he was able to abscond with RAY. Well, at least until the sequel rolled around.
 * Technically, you forgot the real "Patriots" themselves (who also succeeded in their plan...at the time.).
 * By the end of Legacy of Kain: Defiance, Raziel finally stops being manipulated by everyone, and.
 * In Adam Cadre's Varicella, the Villain Protagonist is tasked with manipulating a complex web of court intrigue so that he becomes the last and only choice for Regent.
 * In Final Fantasy Tactics,  However, this example is actually subverted.

Film

 * Happens in every Pirates of the Caribbean movie to date, but especially Dead Man's Chest, with  emerging as the surprise victor.

Real Life

 * Arabia and the Middle East were fought over by the Ottoman Empire, Germany, Britain and France, who were aided by the Rashidis (allied with the Ottomans), the Hashemites (allied with Britain), and the Saudis (led by Abdul Aziz Ibn Saud), along with others such as the Bedouins and the Ikhwan. As the region (plus a good deal more of the area) is now known as Saudi Arabia, it's clear who won. The Hashemites came in second, holding much of Mesopotamia and remaining in power in Jordan today. Most of the rest of the regional powers were devastated and replaced by entirely new states.
 * Also happened in 1917-1921 Russia, where Czarists, Liberals, Anarchists, several Western Powers, Poles, and even a Czech Legion (prisoners liberated from Siberia) intermingled. Who would have bet on the tiny Bolshevik faction back in 1917?
 * The United States might have been this after the Gambit Pileup that was World War One, as all the other major powers were devastated by war and falling apart. Instead, they went back to isolationism.
 * Henry VII Tudor was this, both in Real Life and in Shakespeare's play Richard III.