I loved a lot of Victorian and Twentieth Century British fantasy. From E. Nebsit (the Five Children and It) to CS Lewi s (Narnia), PL Travers (Mary Poppins ) to Phillipa Pearce (Tom's Midnight Garden). Loved Oz, too.
A lot of the books above were series fiction as were my other (non-fantasy) favorites. My sister was into Nancy Drew and the Black Stallion. But I was (and still am) a Trixie Belden fanatic!
I was thrilled to see all the Trixie Belden fans here (Lizstraw, dkshumaker, olmue, andracil)! I have read and reread the 39. Buying the last ones as an adult (and being disappointed with their quality). I buy old hardcover version and still have all my old paperbacks on a book shelf at home.
A few years back I wrote a #40, which can be found here: http://barbln.org/trixie/silent_groom.htm
It's as long as a real Trixie and I tried to capture the style and characterizations, while bringing the characters up to the present day, and rounding out the series neatly. I also made all the characters a little older (Trixie is turning 16).
So even though I would love to write a magical middle-grade fantasy book (and have just the hint of one percolating in my brain). I would have to say the Trixie Belden books influenced me most as a writer. It had been a long-time dream of mine to "write a Trixie". And while a mystery series I was working on for younger kids is one the backburner, DRAWN TO YOU, the first book in a series I created called The Arts-Angels, comes out in September. This was completely influenced by Trixie in that, when I was reading the series, I used to think, "If only I could create my own series where teen characters hang out, work together and help other people." The Bob-Whites were kids from outside of town, so they hung out because they were neighbors out in the country. They came together as a group to solve mysteries, and often in doing so, raised money for charity, saved people from financial ruin, cleared innocent names, etc. To bring it up to today and make it more my world, I created a group of kids who attend a HS of the arts (and major in different art forms) who come together to make music as a rock band, and who help other people through different scenarios. But I totally based in on the Trixie Belden model. I may even write my own fiction where the Bob-Whites and Arts-Angels meet! Ha!