My all time fave is the Maya Wrap!
I use it for my newborn exclusively. I have a New Native Baby Carrier and two other slings with lightly padded rails but I really just prefer the Maya. You can't beat the adjustability or the great fabric!
I carry my 6w old in it all the time, he loves the chest to chest hold. I like the NNBC, but I can't do the chest to chest with a newborn. The NNBC worked well as a hip carrier for my toddler. I haven't tried the Maya as a hip carrier since my 2yo likes to run everywhere she goes!