I have always liked Iam's products, Eukanuba for an active dog.... it's meat based rather than corn (which no digestive system in the world can process)
And important to me, it has no ~unidentified~ "animal" products in it. In pet food label-speak, this means no horse meat or other sweepings of who knows what off the floor at a rendering plant. If it says chicken, it's chicken. If it says beef, it's beef. If it says 'animal' or 'meat' without identifying the kind, it's predominantly horse meat, with a few parts of dead and roadkill pets mixed in. I abhor the use of horse meat, so I go out of my way to avoid it.
Also good around here, you have to read labels to see for yourself, are the premium feed-store brand dog foods. I am buying a chicken and rice food packaged for my local farm supply that is equivalent to Iams. But they'll have differing grades, and you get what you pay for.
Shag here (mom and dad's rather spoiled 6 yr old Dobe) doesn't have a preference (can you tell?) but if he could speak he'd tell you he just LOVES as treats those pigs ears that you can buy at Sam's Club...
No fillers, and has Glucosamine and Chondroiton for joints.
I've had my dogs on this for two years, and they're noticeably perkier, allergy symptoms have decreased (not disappeared), and they love the taste.