My two are on the JWB fish and rice - all that fussy miss Maddie would eat as a youngster, so when Pippin came along the poor lad didn't get a choice, he got the same! They have tried the new(ish) lamb and vegetable recently and enjoyed that as well.
I feed them on the Junior/performance one, as on the adult food Maddie doesn't keep her condition. It's because she's not a big eater, and goes very very skinny very very quickly on adult food. In fact, although they would both be greedy for treats, I'm lucky that they self-regulate their weight. I'm always complemented on how fit they are by both the other dog-walkers, and the vets as well, but can't really take the credit. They will leave food in the bowl if they've had enough, so don't put on weight. All the running and playing they do probably helps as well.