Perforce has the best error messages.

I wanted to know what the path to something was on the server, but I couldn't remember. Little did I know that perforce would be so judgemental:

c:\source>p4 dirs *
//depot/foo/bar/baz
//depot/foo/bar/qux
Client map too twisted for directory list.

And then there was the time I made a perfectly reasonable request, I wanted to edit all the unittest files in the entire tree, and it had to go and get all preachy:

c:\source\v2-dev>p4 edit foo\...*unittest.cc
Senseless juxtaposition of wildcards in '//jeff-src/foo/...*unittest.cc'.

I mean, yeah, maybe there's a typo there, but you don't have to insult me.