you're a lifesaver

you're a lifesaver

You are wonderful and/or helpful. You brought me coffee? Ah, you're a lifesaver. Thank you much for picking up the cupcakes on your way to the party—you're a lifesaver.
Farlex Dictionary of Idioms.
See also:
  • stand on (one's)/its own
  • Mr Right
  • So what if I do?
  • stand trial
  • be on a hiding to nothing
  • Miss Right
  • missus
  • ms
  • be at the mercy of (something)
  • at the mercy of