Anyone see Bedtime Stories with Adam Sandler? He had a ringtone that I nearly died of laughter listening to. A really obnoxious, scratchy voice yelling "RING RING RING!"
But my personal favorite has to be from a friend of mine about a year and a half ago, I tagged along with him in line at the bank for some reason I can't recall, and while there amongst the rest of the customers in line I heard this Italian sounding guy say "Hey buddy, your phone's ringing." Then he repeated it a little louder and more rude "Hey! Pal! I said your PHONE is ringing." From there it only got louder and more rude, then when the guy began swearing, my buddy finally pulled the cell out of his pocket and I realized it was his ring tone. He was laughing his ass off by the end.