This question is almost as tough as deciding between Coke and Pepsi.
Visa and Mastercard have been battling each other since the 1960s; however, it was American Express that really started the credit wars between the giants during the early 1960s.
Amex, as it fondly came to be known, quickly became the preferred card of choice for most credit card users across the world.
The Visa Credit Card First known as Bank Americard when it was launched by the Bank of America in 1959, it was re-christened as Visa after almost two decades.
Now, it is used by more than 21 thousand organizations around the world.
In Europe, Visa has always been more popular than MasterCard or Amex.
Consider these statistics:

• More than 5,000 organizations worldwide use the Visa card
• Visa Europe has issued in excess of 100 million credit cards
• During the last year Visa Europe consumers spent more than 700 billion Euros
• Of this amount, UK Visa users spent almost 130 billion Euros

To combat internet fraud, the Verified by Visa program asks users for a password if they wish to make an ecommerce transaction on a website.
This gives it a clear edge over MasterCard.
MasterCard It was designated as a rival to the predecessor of the Visa card, Bank Americard.
MasterCard was born towards the end of the 1960s, when a group of bankers in California fathered the Western States Bankcard Association.
This was re-christened MasterCard at approximately the same time that Visa was renamed.
Until about a decade ago, MasterCard was the unchallenged leader in the US.
Even now, with growing competition, MasterCard is used in more than 25 million locations across the globe surpassing other cards.
You can get a MasterCard in World, Platinum, Gold, as well as Standard formats and its SecureCode program offers a code which helps prevent the card from being abused online.
Even so, the verification process is not as secure or as well-liked as Visa's is.
MasterCard or Visa? Most merchant establishments accepted both the Visa and the MasterCard.
However, there are clear loyalists for both cards.
While MasterCard is more popular all over the world, Visa is quickly catching up primarily due to its secure verification processes online.
So most consumers prefer to keep one card from each company and use each card according to their individual requirements.
Which one is more popular is anyone's guess.
While each card has its own merits, the safest statistic to believe is that while half a dozen people prefer Visa, six are loyal to Mastercard.