Variant Spellings

[Ostricho]

Not too long ago, in a creative writing class at school, I was writing a story and was describing the "grey clouds in the sky brewing" and received a red editing mark from a classmate.
"You spelled 'gray' wrong," he said with confidence. He was certain he had found an error.
"What? No, you can spell it either way." Suddenly, I was hit with the realization of variant spellings- those small little things, silently dividing the population in a way one might have never realized before.
There are a lot of variant spelling words out there. A lot of these are caused by American English versus... well, I will have to call it "English English". Some variant spelling words include:
-gray/grey
-disc/disk
-canceled/cancelled
-traveled/travelled
-fetus/foetus
-color/colour
-armor/armour
-archeology/archaeology
Sometimes, these differences go beyond mere spelling. One issue I ran into in my even earlier years consisted of writing my 4's with the triangle instead of like an upside-down lowercase h. Even to this day, I find that I am one of the only ones that write my 4's with the triangle.
As I end my babble about word terminology, I ask a question to you- have you had any strange run-ins with variant spellings, or maybe pronunciations? Which spellings do you prefer?