What is the most popular necklace chain?

Could you tell me, which necklace chain is considered the most popular among consumers? Is there a particular design, material, or length that stands out as the most sought-after? I'm curious to know if there's a universal trend in this regard, or if preferences vary significantly based on region, age, or other factors. I'm particularly interested in understanding the driving forces behind the popularity of certain chains, and what makes them stand out in the minds of shoppers.