I'm pretty sure the main part of Hava Nagila is in a major key. My funk band plays a few Jewish weddings each year. The backing chords at the beginning are major with the horn part being minor. We do G major to c minor.
This is purely from memory, but I thought the melody was in a minor key....I guess I was wrong. I wondered why they play this song at hockey games anyway, and I found out that organ players wanted something they could find sheet music for, that sounded vaguely Russian (for the Russian hockey players) :-)