Excuse me.

There is certainly more than one way to use the phrase "Excuse me".  Isn't there.

There's the "oh, I'm sorry, I didn't mean to do that.  Are you OK?" way that your mother probably tried to teach you.

Then, there is the "I'm about to do/say something rude, or in some way inconvenience you for my benefit."  This one can also be just a simple "Get out of my way." as well.

Then, there is the "I'm sorry if you don't like what I said, but heck, someone had to say it".  This one, we usually extend out the "u" sound and add a dramatic crescendo on the ME!...Excuuuuse Me!

It would be great if English had a different phrase to help differentiate.  In the southern United States, where I live now, "Bless his/her heart" is similar, but it's usually only used when triangulating - when the person whose heart should need blessing isn't part of the conversation.

Its just one of those expressions that should probably never be used.  Stick with I'm sorry.  I'm sorry sir, could you let me get by you" is a lot nicer than "Excuse me!".  It keeps the fault or blame with the person doing the talking.