Congrats on the new baby! At first I was thinking rag quilt but:
http://www.quiltingboard.com/main-f1...ies-t4303.html so maybe not. Still I would go with just a basic flannel and/or minky quilt that's soft with a little texture and probably just a simple block pattern. Make two so you have a spare while the other is in the wash.
Rodney