I loved these books as a kid back in the 80's. I'm sure they played a key role in shaping my interests and worldview. These, along with the "Encyclopedia Brown" books, the "The Three Investigators" series, the "Tom Swift Jr" series, and "The Great Brain", plus the original Doyle canon of Sherlock Holmes stories, were constant companions in my youth. Oh, and those "Choose Your Own Adventure" books. Those were great.

Every year the local Barnes & Noble does a Christmas book drive thing to provide books for under-privileged children in the area. I usually chip in at least a few titles, and if I could actually find any of those on the shelf (aside from Sherlock Holmes), I'd probably get some of them, so some young kids today could experience the same thrill.