There are several things in life where you just have to take a side. Marmite - you love or hate it. Mayonnaise - it's either Hellmans or Heinz. Fizzy Drinks - it's either Pepsi or Coke.
In fact, it's the only situation in life I can think of where, upon ordering, you're asked if the other is a suitable alternative.
"Sorry, we don't have any Coke. Is Pepsi alright?" Or vice versa. Reluctantly, you go for it. But it's well known they just don't taste the same.
Yes, we know there are obvious differences between their marketing campaigns and their packaging, but how do they differ in taste?
It's all down to one thing. Their individual flavours.
Coke has a more distinct vanilla flavour, while Pepsi opts for a more citrus taste.
There's also the theory that Coca Cola tastes better when it's from McDonalds.
Apparently, it's nothing to do with the salty food making every sip of your dry mouth appreciate it more. It's to do with the efforts of Maccies to make it taste better.
They use water filtration systems (as 85% of Coke is made from water) as well as temperature control.
There's also the fact that they use stainless steel cylinders to store the syrup in, as opposed to plastic. Keeping it fresher for longer.
Someone's even written a book on the taste difference between Pepsi and Coke. Author Malcolm Gladwell penned 'Blink: The Power of Thinking Without Thinking' and that pretty much sums this up.
It's all about the deceptive power of the mind, and how a snap decision can be as good as one made cautiously and deliberately.
"Pepsi is sweeter than Coke, so right away it had a big advantage in a sip test," he explains.
"Pepsi is also characterised by a citrusy flavour burst, unlike the more raisiny-vanilla taste of Coke.
"But that burst tends to dissipate over the course of an entire can. Pepsi, in short is a drink built to shine in a sip test.
Coke would seem to have the better health kick (if that's possible). Pepsi contains more sugar, calories and caffeine. Although Coke has slightly more sodium.
There is no doubt either that Coke leads the marketing campaigns - the super-brand is available in all but two countries (North Korea and Cuba) - although it's possible it's even being smuggled into these countries.
Even with this knowledge, the debate will never end.
Featured Image Credit: PA