Which shoe type is perfect for flat feet or bunions?

Wide toe box: Any shoe that has a wider base, called a toe box. Most shoemakers have been making wider versions of shoes to provide increased comfort.

Shoe guide: Flat feet and bunions require wider shoes to accommodate the deformity. A rigid, stable shoe is best. No more than 2 inch heels because it puts too much pressure on bunions. More importantly, the shoes have to support the arch whether with built in inserts or store bought inserts. Sandals need to have built in arch supports as well.

None: There is no perfect shoe, except for the shoe that feels comfortable and allows for proper support and enough room to accomodate the bunion.