Application-specific integrated circuit (ASIC) miners are a lot better compared to CPU-, GPU-, and FPGA-based mining since they are designed to perform one specific task only, that is, the mining of cryptocurrencies. An ASIC miner, pictured below, is algorithm-specific:

These hardwares are specifically built to produce high hashing rates. There are various companies that are popular in producing some of the best-performing miners, such as Bitmain, Avalon, Pangolin, ASICminer, and so on.