After Exodia, Final Countdown and Destiny Board, the new instant win card.

In the Yu-Gi-Oh! card game everybody knows they is 3 way to win a duel, reducing your oponent's Life Point to 0, make your opponent unable to Draw, and by card effect.
Until now they was 6 card effect that allowed a player to win instantaneously.

First they was Exodia the Forbidden One who give a instant win when you have in your hand the five pieces of Exodia.

Then appeared Exodius the Ultimate Forbidden Lord which make your win the duel if you send the five pieces of Exodia in the Graveyard by Exodius's effect.

There is Destiny Board, which give a victory after collecting one by one the four Spirit Messages.

There is the forbidden Last Turn, which is a little bit long to explain, so you can click on the name of the card if you don't already know it.

And there is Final Countdown, which after being played give a automatic win 20 turns later.

There is Vennominaga the Deity of Poisonous Snakes who make you win the duel if you three Hyper-Venom Counter on her one by one by infliging Battle Dammages to your opponents.

There is also the Match-Winner Monsters, like the forbidden Victory Dragon.

And now, recently announced to be release in the OCG, after the release of the third playable Egyptien God, Slifer the Sky Dragon (or Osiris the Sky Dragon), there is The Creator of God and Light Horakhty.

The effect of Horakhty is :
This card cannot be Normal Summoned or Set. This card must first be Special Summoned (from your hand) by Tributing 1 "Obelisk the Tormentor", "The Winged Dragon of Ra" and "Slifer the Sky Dragon" each. The Special Summon of this card cannot be negated. If this card is Special Summoned, you win the Duel.

Horakhty is the first monster who give a instant win just by being summoned. In order to do that you have to tribute all 3 Egyptian Gods on your field. Each Egyptian God need to be normal summon by tributing 3 monsters, so your will need to tribute 9 monsters to summone the 3 Gods, and then you tribute all three of them for Horakhty and win.
Monster which can allow you to get extra summons can help summoning the Egyptian Gods, monster like Reborn Tengu, Tour Guide From the Underworld, D-Boys, Super-Nimble Mega Hamster, Giant Germ, Nimble Momonga, and the list goes on and on.
There is the only pic I can get from  The Creator of God and Light Horakhty :

Hope you enjoyed.