The one I dislike is 'no brainer'.
Presumably it means you don't need a brain to work out the answer.
What the speaker means is 'You don't need to use your brain to come to the same conclusion as me.'
What this really means is 'Don't bother using your brain - just accept what I'm saying.'

I prefer 'Go figure' - at least it suggests you do have a brain and you should use it.