Interesting - haven't ever used Mercurial but as far as Windows ports of Unix-based tools go I love the git interface. I always run it in standalone shell mode, and its shell has enough Unix commands built in that I haven't even had the need to install cygwin on my new PC yet. The "check out line endings as \r\n, check in as \n" feature is a neat touch as well (granted, any decent text editor handles both kinds of line endings, but still).