You’re writing a résumé, writing a proposal, contacting a customer, or composing some other written communication for professional purposes. I don’t mean like an academic paper, which has its own set of rules; but business communication.
You wouldn’t write it in Comic, obviously. Courier New is great for some things, but not business letters. According to the people who decide such things for the business community, what is the currently fashionable font for this type of communication?
I’d go with Century Schoolbook. Very easy on the eyes, professional looking. Garamond is very nice too.
Times New Roman and Arial are the ones that I consistently see everywhere.
As far as advice:
I always hear one is meant to pick a sans-serif for internet communication, and a serif for paper-based work and stick with those.
I also have been told a sneaky trick for applications and resumes is to get hold of a range of publications from the company you’re applying to, and use them to figure out and copy their official business stylesheet.
Your idea about using the company’s font is nice. It shows some initiative. However, there is a chance that a big --or design conscious-- company will use an obscure typeface that could be hard to identify and cost $$ to acquire. If that’s the case, then I’d use anything other than Arial or Times. those are the dafault fonts in many, many programs and they look more tired than respectable.
Beyond those points, pick anything that looks restrained and doesn’t bring attention to itself – then get the layout neat and the wording impeccable. You’ll have a leg up on 80% of the other resumes.
…oh, and be aware if your font uses “lower case numerals”, which are designed to blend discreetly into paragraphs without resembling a capitalized word.
They look nice in paragraph text, but don’t line up neatly for columns of numbers.
Example of Garamond with lower case numerals in the bottom right.
Comic Sans.
I prefer the “…Pro” fonts because they include multiple weights useful for varying levels of emphasis, as well as extended character sets. I rotate among Garamond Pro, Jenson Pro, Caslon Pro for formal work, and Arno Pro for more casual publication.
Just to be clear, I am not writing a résumé or filling out an application; nor do I actually need to use a business-y font. I’m just curious about which font is ‘the rule’ for professional presentation.
I see Arial everywhere, too. It looks more ‘casual’ to me. (Maybe ‘business casual’? 
)
The only reason you see TNR and Arial everywhere is because it’s what most office tools default to; a vast percentage of users think of “fonts” as something you change up only for decorative use like a birthday invitation. (Ditto for the more modern Calibri and Cambria.)
To use any other font, someone with experience in page design has to have walked through the production. Otherwise, you end up reading a long report in something horrid and unreadable because the author wanted to be “different” but had no clue that body fonts need to be selected with great, great care.
My experience over about thirty years (beginning before that with Selectric type balls) is that about 99% of the business/professional world doesn’t give a shit about this “font” and “style” crap, and 99% of the remainder reinforce the viewpoint when they try to screw with it.
However… I have strong-armed a few clients into using an unusual font choice for all their materials, and in those select cases they come to both understand it and love it - their reports and memos jump out of the piles and get extra attention even though the readers have almost no clue why. It can become part of a company identity, and pay endless dividends if done well.
There is no specific “rule” when it comes to typefaces (I’ll wait for the typography Nazis to post about the differences between “fonts” and “typefaces”) used in professional presentation. In any case, this would depend on the specific profession that you’re dealing with.
In marketing, Helvetica (or “Arial” to most people who are familiar with MS Word) tends to be used in business settings because it is seen as a modern and “corporate” typeface.
In legal settings, Times New Roman is still the predominant typeface used in my neck of the woods. I’d say 99% of briefs that I’ve come across use TNR.
That’s because the word “facsimile” comes through so well in TNR - almost as nicely as it did in quill pen. 
A. Barbarian’s Rule of Typefaces: The name of of font always looks outstanding in that font, even if the family looks like shit in real use.
Aside: If you have a more general interest in fonts, see the documentary “Helvetica”
My typeface of choice is Times. Times New Roman is “Oh, Look! I’m modern!” band-waggony.
But I was always a rebel.
Times New Roman is a cramped, cluttery default that makes every document a torture to read. I tend to assume anyone who uses it either doesn’t know how to change the font, or is a lawyer (most of whom do not prize clarity and ease of communication).
Cites?
Times New Roman is a cramped, cluttery default that makes every document a torture to read.
It’s not so much that they don’t prize clarity as they don’t esteem it over complying with rules of procedure. Most jurisdictions specify typefaces that can be used in court filings, and most lawyers see no need to depart from those in correspondence.
For example, in Florida all filings “shall be submitted in either Times New Roman 14-point font or Courier New 12-point font.” This rule technically applies only to appellate practice but most trial courts have adopted it in their local rules.
Arial
Well, aren’t we the fancy one, with our esteemed compliance to rules of procedure from which we do not depart?
TNR 14 isn’t too bad, I admit.
So in other words, it’s just your opinion. Okay.
