Which bowl is best for dogs?

Dog bowls are available in many different designs and materials.

Stainless steel
Stainless steel bowls have the advantage of being durable and easy to clean. Most stainless steel bowls are dishwasher safe. It is important to note that the stainless steel bowl has a rubber ring so that it sticks to the floor. 
Ceramic
Ceramic bowls are durable and robust. In addition to the many colourful and varied designs, ceramic bowls offer the advantage that they are usually free from harmful chemicals. Porcelain Porcelain bowls are durable, robust and easy to clean. 
Silicone
Silicone bowls are tear-resistant and usually collapsible. Silicone bowls are therefore often used as travel bowls. 
Plastic / synthetic material
Plastic bowls are usually dishwasher-safe and suitable for everyday use. Plastic bowls are mostly used as drinking bowls