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.