I grew up with most of my quilts tied with yarn, so I tend to prefer a less-quilted quilt over one with a lot of quilting. I usually look for batting that allows quilting to be very spaced out, so I can quilt minimally if I want to, but of course more is fine too.
I tend to quilt baby/child quilts a little more densely than quilts for adults. I assume it's going to be washed more often, and I'm hoping it'll be used for things like blanket forts and superhero capes too, so I try to build those to be extra rugged.