Funny, I just had a conversation with a few friends in the car ride back from my tae kwon do class about what one says after someone sneezes. (This car has me, the American Orthodox Jew, a nonreligious French Muslim of Tunisian descent, a Chinese woman, and a Ghanaian guy whose first language is Twe (sp?), so language and culture discussions are always fun.) I forget the phrase in Twe, but it translates to something like ‘your head should be good,’ which I liked.
I usually say “gezuntheit”, which is what my father says. Occasionally, I’ll use my mom’s version, “tzu gezunt”, to health, although if she’s feeling silly, she’ll use the long form, “tzu gezunt, tzu leben, tzu longeh yar,” to health, to life, to long life. (They’re from different regional variations of Yiddish - my mom’s family is from Lithuania and Belarus, while my dad’s is from Galicia in southern Poland.)
It was loads of fun the first time I said ‘Gezuntheit’ to a member of a group of Germans I was working with here in New York City. The whole lab basically stopped and stared at me in shock, wondering where that bit of German had come from.