Mogli has to work for his treats (freeze-dried meat) - we do a daily round of clicker training. He's very food-driven and looks forward to each session.
I treat. Seems Temptations are the big favorite, my cat goes bonkers for most of the flavors except Tuna for some reason.
But, if you want to treat and feel good about it, I highly recommend Greenies Treats. they have special formulas - Fur and Hairball care, Dental Care, but my kitties personal favorite (and it suits her needs) are the Digestive Care ones. She loves them and with her tummy troubles, they have pro-biotics so they are good for her too.
And sometimes I go with the lowest of the low, Purina(?) makes these soft Whisker Lickins ones that I'm sure are the highest on the junk food list, but some days she won't eat anything... so. Gotta do what you gotta do.
Mia walks straight from the bedroom into the kitchen and waits at the cabinet for me to get her a treat first thing (and only time during the day) she gets up in the morning. I give her the soft Whiska Lickins. She wont eat anything with a crunch, even though she eats dry food. lol Norville smells them, turns his nose up and walks away. Oh she will only eat Chicken flavor too.