I have quite a few materials for science and this is what we're trying out. So far, no clear-cut winners but I just started with the girls today and Pike has his pick of books but seems to simply gravitate towards a simple experiment.
I've looked at Noeo and RS4K and simply reading books and think we'll try a mixture and see what works best. We'll start first with chemistry and then biology and then physics (depending on how chemistry works out).
For the girls, we're going to try Real Science 4 Kids Pre-Level I Chemistry. We've done Chapters 1 and 2 and will do lab 2 this week. I wasn't really impressed with lab 1. I also have two volumes of the "moon" books on order, Winter Moon and Summer Moon, and hope the girls enjoy them.
I'm going to try RS4K Level I Chemistry with Pike in addition to his pick of a science experiment. We have the Earth Science VanCleave book which I'm not all that impressed with. Pike likes it for experiments but I'm not sure he's actually seeing anything from it. Google Books has some of the engineering book and we much preferred it so we'll see about that too. We also have the following (that he hasn't really looked at) Science Experiments You Can Eat; Chemical Chaos; Blood, Bones and Body Bits, as well as 2 TOPS books and one more Sonlight science experiment book. None of these have really resonated with Pike though. I'm hoping the RS4K, Tiner's History of Medicine and a Usborne book I have on order will flesh things out.