Weight loss fads?

I've heard of the cabbage soup diet.  The lettuce and diet coke diet, aka super model food.  I've heard of the grapefruit diet.  I've heard of the vienna sausage diet...ok so that's not a real one but something my BIL came up with.  I'd recommend not doing so he stunk BIG TIME.

I've tried the cabbage soup and the grapefruit diets.  The cabbage soup was really tasty, until like the 3rd day when you began smelling like the cabbage and the taste took on a whole new meaning.  The grapefruit one wasn't so bad, but I can't remember anything about it.

Neither diet worked at all I might add.

What diets have you heard of? And have you tried them?