Similar to the Boxcar Children

Hello!

My husband and I have been sharing childhood books. We have been going through the first five Hardy Boys and the first five Boxcar Children. On weekend we read a chapter each of Hardy Boys and then when we finish one of those, we go to Boxcar Children, etc.

We are about to finish our first five of each series and to add some variety he we are going to do Nancy Drew and another series. Is there another series like the Boxcar Children we can alternate with? Just looking for some simple books to remind us of childhood, simple reading we can do for fun by reading to each other each weekend.

Thank you!