::)Well, I live in an area where most Catholic churches are ethnic in origin, and continue to follow many ethnic customs. I would have to say that the most unusual (for me, that is) custom I've ever seen was a particular Slovak Mass in which some parishoners polka-danced down the aisle.
I was a convert after the Latin mass was abandoned, so I'm not really endeared to it, but as a catechist and Eucharistic minister, I dearly love the Mass as it is today.
Misty