I have three bags this time 
One small labour bag for me. Put in this anything you will need for labour and in the hour or two immediately afterwards the birth:
Old t-shirt, washbag, straw, vaseline, hand towel, oils, snacks, juice, dextrose tablets, one pair of knickers with a pad put in ready, one clean nightie, phone, charger, couple of extra maternity pads, sports socks, pack of cards (ha!), change of socks and pants for DH (it was a long slog last time, a change of socks and pants would have been much appreciated!)
Changing bag for the baby (things to use for the baby straight away)
Blanket, towel, two nappies, babygro, vest, cardigan, hat, wipes.
Having a changing bag means that if you do go on the ward afterwards and need to stay in, you can get your birth partner to load it up with nappies and wipes and a couple of changes of baby clothes so that you're not rummaging around a huge bag trying to find things when baby does a megapoo at 3am
These two bags will come up to the delivery room with me if I end up going to hospital :(
Then -
Main bag (this can be brought out of the car if it's needed - if it's going to be a 6 hour discharge then there's no need to lug it up to the ward, trip over it in the delivery room and then lug it back out again unused!)
Flip flops, nursing bra(s), maternity pads, one nightie, pyjamas (I'm not a nightie girl, even after having a baby I like jimjams), knickers (oversized apple catchers, cheap black ones from Primark), spare baby vests, spare babygros, nappies, socks, carrier bags (for putting dirty things in), thin dressing gown (not a thick one, PN wards are ridiculously warm), more snacks, more drinks.