Only 3 - USA, Canada, and Mexico - but I am young yet.
Someday I hope to have the time and money to travel overseas.
ETA: DH was born in the USA but was an Army Brat, I believe they spent some time in Europe, specifically Germany, when he was a child. His mom says he spoke German as a toddler, but then lost it. Then he joined the USMC out of high school, and has been to Iraq, Kuwait, and Egypt (the "airport" version). He was supposed to go to Japan when the 1st Gulf War broke out, and his orders got changed. He always says he really would have preferred Japan.