I loved the Nancy Drew books when I was a kid - heck I still like them now, but definitely the original, orignals - they were re-written and "updated" in the 50's I think. The first printings have far more interesting language...

I had a big collection as a kid, but they were all sold when I was in college and my parents moved. I have just a couple now, one or two originals and a couple that were reissued just a few years ago in their original state.