From the most common ones, to the more unique ones, I think they're all just beautiful. I picked up about every shell I saw, so I had a big box full when I came home. I also enjoy identifying them. As it seems for almost all marine life, the really beautiful, colorful and showy 'stuff' is mostly found in the warmer, tropical regions.
Seashells are some of nature's most beautiful products.
And although they are as lovely as any flower, they certainly last longer. They are more than just pretty baubles found on beaches. An exterior skeleton is very important to these creatures, providing them with shape and rigidity. Their shell also provides protection, and sometimes camouflage, from predators. Interestingly, a squid is also a mollusk.