I was going to add all the Encyclopedia Brown books to this one review, but BL's book search sucks (entered an ASIN from a BL book page and yet BL's search couldn't find it! Magic!)
Anyway, in a fit of nostalgia, I'm re-reading my way through this series. I've always loved Encyclopedia Brown, and I remember back 30 or 35 years ago I was always running to the library to see if they had any new ones. They're fast, they're entertaining and very well-written. It's so easy to devour one in a half-hour and yet you're just as satisfied as if you read a full length novel.
So, this review will sum up the series for me: great for kids, and even better for adults.