They get the new Science Diet dry food (the one with all the cute little shapes and flavors) and they love that.
I've been alternating between Science Diet canned and Nature's Balance (I think) Ultra, also canned. Alternating because they're picky. They'll scarf up one can of one food really fast for a week or so, then they get tired of it and will hardly touch it again, but if I put down the other type they go for it like crazy again. Normally they say it's not good to switch foods on them like that, but so far I haven't seen any stomach problems in any of the kitties due to switching foods.