I also have to do this by park:
In MK:
Best: Cosmic Ray's- this place is just a classic
Worst: Golden Oak Outpost- just needs more selection
In Epcot:
Best: Yorkshire County Fish Shop- a hidden gem- sooo cute and so good!
Worst: Cool Wash Pizza- just so random!
In DHS:
Best: Starring Rolls (ohh those cupcakes

)
Worst: Rosie's- barely any selection and nott good.
In AK:
Best: Flame Tree BBQ and Pizzafari- both have really cool atmospheres and good food!
Worst: Tamu Tamu Refreshmants- again...needs more selection
In DTD:
Best: WPE- so many options and great portions for a CS credit! It's almost unbelieveable!

Also I love EoS- lots of options and they're all great!
Worst: I can't really think of one...maybe McDonald's lol. But that's gone now...so I don't really have one...
At the Resorts:
Best: The Mara at AKL- great selection and I love the atmosphere! Plus it's a nice walk there by the pool

Worst: Good's Food to Go at OKW- like absolutely NO variety at allll.