What to do with that last comma? Yeah, you know the one I mean.

Keep the comma, add something else to the list, or trash it altogether?  OR I could think about it some, get another beer and relax.
That second comma in the first sentence is called an Oxford comma.  Hey, I’m with you — never heard of it until today.  But for years the necessity of that comma — the final comma in a list — has been debated not only by grammarians, but by the geniuses in Marketing.  See, they want that last comma tossed out — to make their crap easier to read by the Great Unwashed and Unedjumacated.
But, lo!  Today this article appeared, and I suggest you read it for your entertainment, enlightenment and, um, edjumacation.