I've been to Frankfurt a number of times although not during the Christmas Markets. There are some nice areas but I find the city has a little less of the charachter and charm that draws me to Germany. I think the Christmas Market is held in Romer the square there is nice but not spectacular IMO. We'll be flying into FRA but I don't have plans to spend any time there this trip. I'll also be interested in hearing from anyone that can comment on Christmas Market there.