The thing I hate is when testers file a bug that says "When I do steps 1 - 37, I get an error dialog." I end up spending a couple of hours whittling down the bug only to find out that all you need to repro it are steps 36 and 37.

I know in some cases the testers are trying to be complete, but I also know certain testers whom are either lazy or to whom just don't think to search for a root cause.