However my all time favourite series had to be 'The Chalet School' series by Elinor M Brent Dyer. This series is epic - the first book was written in the mid-1920s, the last one in the 1950s. Some of the books were split where they were published as paperbacks, so there were about 60 books in total in the series. Armarda never had more than six or seven of them in print at any one time. It became a bit of an obsession and I religiously collected as many as I could - even when I'd really out-grown them. By my early 20s I probably had about half the series.
Then, one day, I hit lucky in a second hand bookshop near Manchester. Mark noticed a box with some familiar titles under a table. We pulled it out and discovered almost all the books that I was missing in the series. It was a 'now or never' moment... we bought all the books I needed to complete my series in one go. I think the owner of the shop thought we were crazy - seeing two adults pouring over a box of rather tatty vintage school stories!
My Chalet School series sits on a couple of shelves in a corner of my study - chronologically ordered ofcourse! In reality, I still have one book missing but I don't think it was ever published in the paperback series. I still read them from time to time and I'm immensely proud of a collection that took almost 20 years to complete.
Do you have any on-going collections that have kept you occupied for years?