I've liked this one since its origin in Melee. While many would assume this item comes from the Ice Climbers game, but it came from the Mario Bros. arcade game as a notable enemy.
While you can throw the freezie, since its ice, it can be a little tricky to catch as it slides around the stages.
But if you can hold one and hit your opponent with it, it causes them to freeze in ice for a moment.
And I mean just a moment, it doesn't last very long. While it's more on the "useless" items side, I still think it's fun to use. I'm not sure why.