Generally, every website should be simple, but attractive. The Magento store provides a wide choice that suits many sites. Top popular themes are Tiffany, Complex, Sneaker, Devita and Mag2 Marketplace. And also remember in case you have enough resources it is better to buy a paid theme or to develop a custom theme from scratch. This will make you more unique among other ecommerce players and ensure the right match with your project vision.