The Secret Seven books were probably my favourite series of books as a (young child). I absolutely loved them and used to read them over and over again. The copies that I had were my mum's books from when she was a child in the early 70s, so they were yellowed and very old, but the originals (as I think I read that today's copies have been edited). I read them so many times I'm surprised they didn't fall apart.
This collection however which contains the first three books in the series I used to take out from the library over and over. I must have borrowed this book from the library over a 100 times. The only thing is I don't think I ever read 'Adventure' over and over again as it is my least favourite of all the books.
Unfortunately I had to get a new library card and can no longer go back and look at all the books I have ever borrowed, but when I did I found out that I first borrowed this book in June 2000!