Second the giant Aden and Anaïs muslins. I was gifted some for DC3 and wish I'd had them with the others. Perfect size and grippiness for swaddling, great travel blanket, used as a cot sheet, playmat, picnic blanket etc
Also really liked Cuski muslins/blankets for the same reason but had some great colours. Also Faye and Lou standard sized smaller rainbow muslins.
Snooza breathing babymonitor.. Now this wasn't as great as I'd hoped and many would say totally unnecessary. But I found those first few days after the birth when you haven't slept off the birth yet and the baby is still doing that terrifying erratic breathing that they do, then the Snuza was great for that first week so I could actually let myself go into a deep sleep and not be tipped into exhaustion. I can't remember how long we used it, but there was a night where it kept going off for no reason and I ended up flinging it across the bed and not putting it back on-that was when I knew I didn't need it anymore... But I sold it for the same amount I paid for it on eBay. So it was a win win I think. Definitely glad I had it for the early days.
I was passed on a gorgeously silky soft bamboo
Bath towel that had a bit you could popper round the parents neck so it was like an apron on you. Friend said they didn't see the point of it but I loved it! It made it so much easier to get them out the bath and covered up.
And lastly, a wipes warmer. Not really a big product in the UK but if you can find them, I love them for newborns. I used it with cloth wipes or kept it full of cotton wool and warm water. Even with baby 3 I couldn't bring myself to use cold wipes or water on their little newborn tush, especially in the middle of the night!