BZIP2 compression does seem to offer the best compromise between compression time and compression ratio, as reviewed here: http://odzangba.wordpress.com/2009/03/25/gzip-vs-bzip2-vs-lzma/. I was looking for quick and efficient way to zip up some old files for back up. Bz2 won out for me.

I’m using Ubuntu 12.04′s built-in compression tool.