Old school is 2 commas, and what I use. New fangled acceptance is one comma. Stay with two. You will look more intelligent to people in the know 
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two commas is more precise. One comma can lead to ambiguity. For example, are you to pick up ham and (turkey and bread) or ham and turkey and bread. Your example is hard to mess up but there are other contexts where one comma can lead to ambiguity. It is also lazy IMNSHO to leave it out. But it has gained acceptance to do it that way
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Both are just fine.
Both are acceptable, and have been for the last 30 years since I was in elementary school.
That’s the problem with English teachers and copywriters, they want to apply rules to language as if it was math. It’s not math, if used correctly it is art
Yep.
One comma is more correct.
Overuse of commas is something I’ve struggled with grammatically.
this…
Brits would use the extra comma, if that helps (for or against). 
M_P
Because when you speak, you do slightly. However a pause in speaking does not mean a comma or a lack of a pause does not mean lack of a comma. Spoken and written language is not the same or I should say there is lack of one to one correspondence.
You pronounce
I am having bacon, eggs, and ham
and
I am having bacon, eggs and ham
the same
one comma looks really funny to me since unless eggs and ham are a single complete unit, there is nothing to show that they are not.
The examples I saw did not create ambiguity – they only changed it. The examples they gave were ambiguous with and without the extra comma. The ambiguity changed when it was added or removed but it was not a case where one one was ambiguous and one not. In those cases the sentence needed to be reworded.
“Around and around the horses, lions and tigers would move.”
I received this sentence from an author of a children’s book I edited. It was about a merry-go-round, so the lions and tigers weren’t supposed to be going shark on the horses. Instead they were moving around the merry-go-round, as in: “Around and around, the horses, lions, and tigers would move.”
With either style you have to be careful, but I’ve run into more instances where the lack of the serial comma caused trouble, as opposed to the other way around.
Which one you use though, really depends only on which one you like, provided you understand and can recognize the problems with each. Usually folks have one or the other specified as part of their house style. You’ll see the Oxford more in books, whereas newspapers and magazines drop it (fewer characters=less typing, less space taken)
If they don’t apply rules, then they can’t give a grade. And if they can’t give a grade, how can anyone know if little Johnny’s learning?
There’s no real rules in written language, only conventions to be followed or broken, depending on audience and intent.
The Harbrace Handbook is generally considered the final word in all things written, documented, cited, etc. in most US universities.
From the 2008 edition: A comma appears after each item in a series except the last one.
The MLA Handbook, 6th edition, advocates the serial comma. So also the Chicago Manual of Style, Strunk and White, Fowler’s, Oxford UP, and Harvard UP. (At least last time I checked)
Advocating against the serial comma is much of the world of print journalism, including AP, New York Times, and Los Angeles Times.
I taught 8th grade grammar for 15 years.
Bad teachers teach one rule or the other, grade their students based on an arbitrary choice, and send their students out into the world filled with false certainty soon to melt into grammatical confusion.
Good teachers make sure their students understand what is at issue, why there is more than one approach, grade according to their students’ measured understanding, and send their students out into the world with something called an education.
I’ve always thought it was a comma after everything but the “and” if separating more than one thing.
Also, not to be picky, but aren’t all numbers under 10 supposed to be spelled out?
i’d go with how captain kirk would say it:
Please. Pick up…ham. Turkey. And bread. Fromthestore.
It depends on the manual of style you use. For Chicago (mostly history), all easy numbers (i.e. one thru ten, fifteen, fifty-two, two hundred and fifty, two million etc.). More specific numbers (i.e. 1,245,609) should be done in arabic numerals. MLA is more specific to the discipline of English Language/Lit so I’m not sure what it says, but it’s not the only authority.
I’ve had academic historians/professors have docked me for adding a serial/oxford comma so increasingly its falling out of style at least in the discipline of history but I’m sure it all depends on the individual. My abridged version of both MLA and Chicago Manuals say it’s “optional”.
Militarymoron…LOL… I’m laughing so hard I can’t get the cursor on the post reply button:p
Dang that is funny!
My classical English education said 2 commas and when I worked as a journalist the “comma” combined with “and” was considered redundant and I now consider English more as art and make it up as I go
You gotta love the Big Brains tote’n M4s around… I’ll bet the Anti-Crowd would never believe or report that a discussion like this could exist on a forum such as this