Aluminum
I don't remember where I first came across "aluminium", but it was not more than a year ago. Thankfully I've never had to endure someone pronouncing it, and it's rather easy to ignore the extra I. Today I somehow got on the subject again as I was aimlessly surfing, and decided to find out just what the real story is. You see, the Brits will swear up and down that aluminium is correct, and most North Americans are oblivious to the fact the the rest of the English-speaking world prefers aluminium over aluminum.
As I see it, they're both correct, but aluminum is preferrable. They're both correct because standards bodies say they are. Some group of important people in chemistry in the US declared aluminum correct, and likewise in England aluminium was declared correct. International groups prefer aluminium but recognize aluminum as a variant.
So shouldn't I do the cosmopolitan thing and accept aluminium in spite of my American blood? No, because the Brits named it aluminum in the first place. Ok, the one Brit who discovered it and had the privilege of naming it: Humphry Davy. He first named it alumium, but then changed his mind to aluminum, to match the Latin root. Then the equivalent of a high-brow Anonymous Coward Slashdot comment in the Quarterly Review (a British political-literary journal) strong-armed the usage of aluminium because it sounded "more classical". I kid you not:
Aluminium, for so we shall take the liberty of writing the word, in preference to aluminum, which has a less classical sound. (Q. Review VIII. 72, 1812. Cited in OED.)
Davy didn't stick up for his original spelling, and apparently used both interchangeably. So did the rest of the world for 30 years. Then aluminium became commonplace everywhere, including America. I've heard conflicting reports as to why we went back to aluminum, but go back we did and I say it's at least as correct as the other spelling. You can tell any Brit that won't concede that point that he's a 19th century couch taxonomist. That ought to be fun.
But the real reason I prefer aluminum is simply that it's so much easier to pronounce, and my tongue is lazy. Forget what you grew up with for a moment, wouldn't you rather have four syllables over five? Aluminium is also a bit tongue-twisting, but of course the British love a good tongue-twisting word so that's not a good argument.
Well anyway, there you have it: more than you ever cared to know about aluminum. A nice good authoritative-looking reference without all the opinion and babbling you find here can be found at transporteon.com.