People debate the usefulness of the Oxford comma and fret over the use of any comma, but one little comma can change everything.
Here's a charming example from a t-shirt I saw:
"I love barbecuing my friends and my family." Underneath it said "Don't be a cannibal, use a comma!" lol!
Last week, on Jeopardy, the Oxford comma was one of the answers. The question was: "I greatly admire my parents, Superman and Wonder Woman." Unless you're a superhero (and maybe you are), you need an Oxford comma after the word Superman.
Who says grammar can't be fun? For more grammar tips, check out my book "Teatime with Mrs. Grammar Person," which is free on Kindle through April 16. :-)