I have almost all of these, as well as a collection of YA books - I went to graduate school so I could teach high school English, and "had" to read teen lit to pass

I have four boxes of books for the nursery, and I registered mostly for books...
One note about racial slurs in the LH series - the Little House books have Ma expressing hatred born of fear towards the Native Americans, but Pa disagrees with her... except in regards to using the land (he thinks the white settlers use the land "better" and therefore deserve it). Laura, on the other hand, feels something is wrong with both of those attitudes, and it shows. It's a very complex relationship and one that made for a lot of good discussions with my own parents (who are very committed to justice and equality). In other words, I think it's too good a jumping off point to skip the books for a kid of the right age. Also, Little House In The Big Woods has no racial issues at all, and it's the easiest to read of the books - the series ages just as the readers do, not unlike good ol' Harry Potter.
There is one fairly hideous "minstrel" show in one of the books that I intend to just skip the first time I read the book aloud, and use as a teaching moment later on.
This is one of the only series that have girls as main characters that boys also enjoy. For many of the guys my age, this was the ONLY series they ever read with a strong capable female as the lead.
I love Louisa May Alcott's books (I haunt antique stores for them, I have most of them in first or second edition!) but even a devoted fan can see how the author's political awareness changed from one book to another

I think many of these older books can really show a kid how history and perspective changes, without being dry and dusty.