Do what you want, but I’ve said them both out-loud 100 times and I’ve decided Twenty-Ten sounds better than Two-Thousand Ten.
We called 1810 Eighteen-Ten and 1910 Nineteen-Ten, so why would we pronounce 2010 Two-Thousand Ten?
Only because the past decade has put us in the habit of saying Two-Thousand This, Two-Thousand That. That worked fine through today. Twenty-Oh-Nine? Clunky!
But Twenty-Ten is cool, crisp. Say “Two-Thousand Ten” and it sounds like you’re playing hide-and-go-seek and you’ve been “it” long enough for everyone to hide in the next county.
Despite this, the author of the Cambridge Encyclopedia of the English Language, David Crystal, predicts that most people will say “Two-Thousand Ten” because he thinks it has a nicer rhythm and flow than “Twenty-Ten.” I say he’s a man with a great mind but a tin ear.
But we do agree that 365 days from now we’ll all call the new year “Twenty-Eleven” because “Two-Thousand Eleven” is so ponderous that saying it even once makes your jaw hurt.
But Twenty-Ten. Now, that sounds like a good year.