Im a little informal, so more like say, ‘hey there Ron, what’s up?’
Well, he got some new shoes over the weekend…so this week we’ve been calling him “Squeek” (but we know where he is at all times)
Other than that: first name. Very informal here.
Always by first names when speaking to them.
There was one guy two levels higher on the org chart that was referred to by his last name (No Mr. or Dr., just last name) when he wasn’t around, but that was to avoid confusion with a programmer who shared the same first name.
Other than the time I worked for doctors, I’ve always called them by first name. Even now, my boss is old enough to be my mother and I call her by her first name.
It depends on where you work. If you are, say, in the police, you will always address your superiors as “sir” and “madam.”
I call him “Chuck,” not “Your Royal Highness.”
j/k
I have always addressed my superiors on a first name basis.
First name, although there are people in the company who address the CEO and other officers as Mr. with their last name. Our district manaeger addresses the Executive V.P. as Mr., and the V.P. addresses him by his last name - that’s not a respect thing, though; it’s a manifestation of their strong dislike for each other.
I do use sir and ma’am often enough in conversation, and Mr., Ms. or Mrs. (when I know it’s preferred) in certain situations.
It really depends on how they address me.
If they consistently refer to me as Mr. Caught@Work, then I will respond by referring to them as Mr/Ms, etc.
If they prefer to refer to me as Caught then I respond in same.
I believe equality as people, not education, comes into play in the work force, so I will treat them as they treat me.
All my bosses, from my direct supervisor all the way up to the president of the company, go by first names to everyone who works there.
(last name)-san. I call some other people in the office this, but most others have a nickname they use with the less formal “-chan” ending. This place is a lot less formal than most places I’ve worked.
“Hey, Pam.” “How’s it going, Steve?” “Hi, Ginny.”
(They are a department chair and two division deans. It ain’t no military academy.) 
When I was a teenager, I worked for a while at “Best Products”. (NOT, “Best Buy”.)
They REQUIRED that we call out fellow employees by their last names. Miss Jones, Mr Davis, etc.
In my current employment, I refer to everyone by their first names. Including the CEO, President and Chairman.
GAD! I LOVE being the travel-guru!
That sounds very informal. I think most people in Japan address their superiors by title, not name. I call address my boss (advisor) as sensei.
scr4, it is pretty informal, but that’s the way he runs the place. When the Chairman is talking about having shaved his balls, the President is inviting everyone to the performance of his rock band and the accountant (female) jumps on every man in the office and wrestles them to the floor at drinking parties, it encourages a measure of casualness
When he’s not around we call him “Our Lord” (because he thinks he is 
), otherwise he go by his first name.
BTW this is my first post - be gentle.
LumberJack
I believe in an equal society. You call me by my first name, I call you by your first name. This applies to everyone–bosses, doctors, dentists, everyone.
Well, in the Army, it was “sir,” “ma’am,” or in the case of NCOs, their rank or title. 
In my company, always first name. Even the President and the Directors would probably ask me to call them by their first names if I addressed them as “Mr.” or “Mrs.”
Point my finger and laugh. Or throw something. Or, the ever popular, “What?!!”
'course, we have a kind of an odd situation here… my bosses are John and Steve, and the three of us have been training karate/sword with their boss, Dave, for about six years; plus, the three of them were in the military together, so it’s kind of loose.
I call my boss by first name, or “boss,” however she refers to herself as “the bitch in high heels.”
In Sweden we´re pretty informal. In the two “real” jobs I´ve had, in parliament and in a consulting firm, everyone has always used first names.
The only place I´ve used titles was during my military service.
Lawyer in government law office - call everyone above and below me by 1st name - up to the level of presidential appointee (whom I meet only exceedingly rarely). I think most of the support staff call most of the lawyers by 1st name.