The backsplash is both an opportunity to be decorative and utilitarian. If you are a cook and use your stovetop quite a bit, then opt for materials that are durable and cleanable like ceramic tile or stainless steel. Some natural stones will do well, while others may show grease more easily. As a rule of thumb, I tend to avoid glass tiles behind the backsplash, especially around the cooktop, as the grease may show streaking.