Mortal Kombat Arcade Kollection

Do this after you've nabbed all the other achievements as they'll count towards the 200.

The quickest way:

Two controllers. Select UMK3. Pick the first characters that are selected. On the 'Kombat Kode' screen you want 044440.

That is to say on controller 1 press RT and B four times and on controller 2 press RT and A four times. Do this simulateously. It's a bit fiddly at first but it makes the next match one hit kill (and just one round too!). Speeds things up A LOT.

The achievement will pop right away when you get the 200th win.

Note: this can also be done in single player and online matches (but will take a bit longer).

The 200 wins needed for this achievement are accumulative across all three MK titles. It does not matter which MK title you are playing or if the win comes from a VS CPU, VS Offline Human, or VS Online Human match -- they all count toward the 200 win total.

Can easily be boosted with a 2nd controller. If you don't have a 2nd controller, just play through the Arcade Ladder multiple times or hop online.

To unlock this achievement, you have to win 200 matches. This officially means that any and all matches you win will count towards the achievement, whether it be in single player mode against the AI, against a human opponent in a local setting or against a human opponet on Xbox Live.

The way I unlocked it is to meet the neccesary conditions to unlock the other 11 achievements and then went to UMK3 and do single player on the Novice Ladder. From there, i pick Sonya, whose Leg Grab move is spammable up to a certain point and keep on playing until I lose a match. From there, i let the continue timer (and whatever timer there is to unlock the three hidden characters) run out and then start again.

An intermediate player can get around 2-3 wins in a row on the novice ladder before the AI goes Ape**** on them. Keep doing it until the achievement unlocks itself.

This is known to be the longest achievement in the game. You must win a total of 200 Matches. Rounds do not count as the wins. You personally have to defeat the opponent and let the announcer say "Finish Him/Her" in order for it to fully count.

As PeaceSquid said in his solution, there is a Cheat you can use that allows you to K.O an opponent in just a couple hits. But you will need a 2nd controller in order to do this method as A.I opponents will just smack you quickly.

The unfortunate thing about the Cheat is you will have to enter it each time you start a new match against your 2nd controller.

You need to choose "Ultimate Mortal Kombat 3" and then get to the "Character Selection" screen with one of the controllers. Press on the 2nd controller to activate it and then choose your characters. Now when you see a picture of the characters and Battle 1, you should see 6 boxes at the bottom of the screen. This is where you need to enter the Cheat to activate it. And yes... you have to enter it in every new match you do, otherwise you will have to complete 2 full rounds against your 2nd controller instead of one. Let me remind you as well that you only have a few seconds to enter the codes for both controllers and if you fail to enter it, the cheat will not be active in the round your playing.

So the cheat you want to enter in this menu is 044440. That means you must ignore the First Box & The Last Box (keep them with the Mortal Kombat Logo Picture) and change the remaining boxes to a picture of a ? on each of them. This is the 4th code in the game.
Player 1 has access to change the first three codes on the left side of the screen. Player 2 has access to change the last three codes on the right side of the screen. As a team the 2 controllers must work together to enable the cheat to work. By default the buttons Player 1 needs to press are x4 & x4. Player 2 needs to press x4 & x4. As you can tell if you are the lonesome person using 2 controllers this can be confusing. But I can help you out with that in a moment. Keep reading.

If you've successfully entered the code correctly before the match loads, then you should be given a message at the bottom of the screen. You and your opponent will have 1 Round won each as well as your energy at the bare minimum. Now just attack your 2nd controller once and the announcer will say "Finish Him/Her". Do a 2nd strike and you will win the match. Match completed in just a short moment. One down many more to go.
Press on the 2nd Controller on the Kontinue Screen and then return to the Character Selection Screen. Rinse and repeat everything above for each lobby before the match begins.
With this method you can get around 2 - 5 matches done in 1 Minute. Judging by this, if done correctly it is possible to get this achievement done within 1 Hour or possibly less. If your doing this in one sitting, the game will keep track of how many Battles you have done, so you can use that for recording. Other than that it's pure guessing as the game does not have a Stat screen showing you how many wins you've got. The achievement will pop on the top left side of the screen after you have won your final match needed to get it.

Tip For Entering Code

Because you only need to do a couple hits to win a match against your 2nd controller and you have to enter the code in each match you do, I personally found the best method is to change your Controls in the Options Menu to make it easier for yourself when entering the codes.

Whilst your in the game press and choose Options. In this menu press Controls and then press on the opposite controller that's not on the screen at the same time. Now the buttons you will want to change by Default is & for Player 1. And & for Player 2. Here's what I suggest...

Player 1 - Change =
Player 1 - Change =

Player 2 - Change =
Player 2 - Change = (This might have changed already because you've assigned to the selection, but make sure you change it for yourself anyway)

Accept these changes and then return to the game. Now next time you enter the cheat, instead of shoving your fingers to the back to press quickly on the 2 controllers, you can now go at ease and just press & on both controllers to enter the code and activate the cheat for each match you do.
When it comes to fighting against your opponent since your controls are different, just use the button. That move hasn't been taken and you can use this to defeat your opponent in a couple hits.

I would suggest above all to save this achievement until last. You will likely have around 20+ wins towards this achievement after you have obtained the other remaining achievements in the game.

Good Luck!