at this very moment it would appear that rv has the upper hand, but should jyp choose to give twice some solo content (mostly variety) they might just come back on top of the charts
i'd say kep1er, they come from a survival program and they have already sold great numbers, but they are not permanent, so it will hurt them in the end.
billlie seem too experimental for gp's taste, so i'd say it's between stayc and ive.