This may not go anywhere, but I have a pair:

cricket = kosher

Um...hot dog = hallelujah?

Of chorus.

As someone who has been around teenagers waaay too much:

bad = good

cerulean = sky-blue

hot=cool?

This one closer to the basic idea? ( one whole week of thinking )

peanuts = trifle

hogwash = dictionary

not to mention from the same source

wicked=good
sick=good