There was a poster here once with the handle <i>'MACDaddy.'</i> I thought it was one of the cleverest handles I've ever seen. Also, I wondered why noone ever called the NASD <i>Nasty</i>. Too obvious, I suppose.
We always called it Mack-D. Of course we also say "klack" instead of KLAC, "ay-mat" for AMAT, "pet 'em" for PETsMART (PETM) and "inferior but marketable" for IBM