My cats have been picky lately too. I switched them to Innova EVO and they all LOVE IT! It is very smelly and so is their poop, but that may also work too. It actually smells good, but strong.
Also Purina Pro plan has a soft food with sardines and tuna, and it is REALLY smelly. ( it comes with whole chopped up sardines, imagine my surprise when I found fish heads in the cans) lol