We had the same problem when we got our Sophie. She would pick out Charlie's adult food and he'd pick out her puppy food. Both were Purina One. We gave up and just fed them Adult.
I've seen the the light and have just this weekend started moving them to Natural Balance (original Ultra for small breeds, small bites) which is good for puppy and adult and it not crap food.
First time they got it, mixed in the bowl (Friday night) with the Purina, they picked the Purina out and left it on the floor.
So they like the NB.
The ugly part of the switch is that our 2 year old went out about 1 AM and pooped which is rare, but he goes out when he needs too or didn't go before bed time. I had reason to track it down on Saturday and found it started out normal and went to loose then he made it back to the deck and loose again then he ended up with a messy bottom and in an attempt to clean up, he left messes in about 4 places in the house before making it back to bed, next to me. Obviously he had a problem controlling it once it went "bad".
Saturday morning was quite the cleaning event.
He's been fine ever since, and still tries to pick the NB out.
I think others gave you links to the food thread which is a great read to augment your own research. I don't know hoe long I looked in to it before I went looking for choice #1 and #2. Found our local Petsmart doesn't carry a lot of what they say they do, or do on-line in the store so I ended up at Petco and they had everything.