Lemonade used to be very popular in North America, but the canned and bottled drinks have taken over.

Still, nothing better than fresh squeezed lemons, water and sugar to taste. Chill, and pour over ice cubes in a tall glass. Fizz? Haven't tried it, but bottled selzer water (Canada Dry Club Soda or the like) might do the trick, wholly or partially replacing the water.

Fizz sounds a little like gilding the lily. (I have added a little sapphire gin when no one was looking).