What is the most popular bridge in crypto?

Could you elaborate on the concept of a 'bridge in crypto' and provide an insight into which one stands out as the most popular? Given the dynamic nature of the cryptocurrency landscape, I'm particularly interested in understanding the features and benefits that have propelled a particular bridge to the forefront. Could you also touch upon its impact on the industry and the challenges it faces in maintaining its position? A detailed explanation would be invaluable in helping me grasp the significance of bridges in the crypto ecosystem.