greatest thing since indoor plumbing

greatest thing since indoor plumbing

 and the greatest thing since sliced bread
Rur. the most wonderful invention or useful item in a long time. As far as I'm concerned, this new food processor is the greatest thing since indoor plumbing. Joe thinks Sally is the greatest thing since sliced bread. You can tell just by the way he looks at her.
See also: great, plumbing, since, thing