You say/like tomato

This is so well known it's arguable whether it's just a regular meme, along the "Beam me up Scotty" lines, rather than the multiple-universes Mandela Effect some would put it down to. 

Nevertheless, next time you meet someone ask them to quote the line and you may be surprised how widespread this is. 

George and Ira Gershwin

The whole song is a joke many couples can relate to. If they can't even agree to the little things, what's the point of the big things too, like staying together? It's done in such a lighthearted way though, that everyone is in on it and know full well these little differences will be laughed off and they remain together as strong as ever.

Let's call the whole thing off

Here are the lyrics

Verse:
Things have come to a pretty pass,
Our romance is growing flat,
For you like this and the other
While I go for this and that.
Goodness knows what the end will be;
Oh, I don't know where I'm at...
It looks as if we two will never be one,
Something must be done.

Chorus:
You say eether and I say eyether,
You say neether and I say nyther;
Eether, eyether, neether, nyther,
Let's call the whole thing off!
You like potato and I like potahto,
You like tomato and I like tomahto;
Potato, potahto, tomato, tomahto!
Let's call the whole thing off!
But oh! If we call the whole thing off,
Then we must part.
And oh! If we ever part,
Then that might break my heart!
So, if you like pajamas and I like pajahmas,
I'll wear pajamas and give up pajahmas.
For we know we need each other,
So we better call the calling off off.
Let's call the whole thing off!

-- Let's call the whole thing off