On a purely compression algorithm front, the recently format-stabilized [1] zstd [2] beats the pants down Brotli, in terms of compression speed, decompression speed, and compression ratio. Zstd isn't some random effort either, but a more flexible (in terms of compression time-for-ratio) effort by the creator of the popular and insanely fast lz4 compressor[3].
[1] http://fastcompression.blogspot.com/2016/06/zstandard-reache...
[2] https://github.com/Cyan4973/zstd
[3] https://github.com/Cyan4973/lz4