The best, -est いちばん

While it means #1, it is also used as a superlative- most or -est

食べ物の中は何が一番好きですか？
tabemono no naka wa nani ga ichiban suki desu ka?
Out of all foods, what do you like the best?

富士山は、世界で一番高い山じゃない。
fujisan wa sekai de ichiban takai yama ja nai.
Mt. Fuji isn't the tallest mountain in the world.