The British spell this word "judgement," while Americans spell it
"judgment" (that's why Webster 1913, an American dictionary,
contains an entry for the latter but not the
former). Lawyers, judges, and English teachers are known to be sticklers
about the proper spelling of this word.
Now, normally I myself am anal about conforming to standard
American orthography (and if I were a lawyer, a judge, or an
English teacher, I'd probably still be anal about it). That said,
judgment looks awful, at least to my eyes; every time I read it, I
mentally try to pronounce it as jud-glottal stop-ment. I can't do
glottal stops very well--not even mentally--so usually I end up coughing.
"Judgement" is therefore one of the only misspellings that I actively
endorse. I maintain that everyone should spell it the British
way; it makes more sense--after all, we don't write "placment" or
"easment" or "amazment" (or, for that matter, "judgship")--and besides, it looks prettier.
Several noders tell me that current American dictionaries maintain that either one is correct. Curiously, my 1999 copy of Webster's lists both as correct, but simultaneously maintains that 'judgmental' and--stranger yet--'judgment day' are supposed to be spelled without that extra E. Nonetheless, legal dictionaries apparently still mandate 'judgment'. So now we just have to convince the lawyers....