Mint won the flavor wars, over years and years.

Some of the first flavored chewing gum was... pine-flavored. Cloves, licorice, cinnamon, and more got tried. I used to love cinnamon flavored toothpaste as a kid. Somehow, peppermint, regular mint, spearmint, and wintergreen sold best.

In Taiwan, I saw a lot of odd flavors like green tea, but mint was still most popular. And kids' brands come in bubblegum and citrus, etc, so there are some other flavors put there.