> I don’t know of any good replacement…
My Chambers dictionary suggests these alternatives: actually, really, absolutely.
It also says, "literally is in common use to intensify an idiom, and this is not incorrect".
My general rule is that usage defines meaning. If lots of people use literally as an idiom intensifier, then I'd be wrong to argue. However, my GCSE English teacher said that we need to consider the intended audience and form. Me saying, "They literally flew down the road" to my mates in the pub is fine. It is not fine in formal writing.