I am quite eclectic. Many years ago I was initially attracted to certain vintage IWC models (Ingenieurs), and spent a few years mainly focussed on them. Then, over time, my interests widened, and I began the long, interesting journey that continues to this day. I do focus mainly on watches from the 'Golden Era', which I would say roughly covers the mid/late '40s through the early '60s. This period produced, in my view, the very best watches across a fairly wide spectrum. By that I mean not only were the top-class makers (e.g. PP, AP, V&C) producing iconic masterpieces, but even mid-high brands such as Longines and Omega were at the top of their games. Not only did they produce superb chronometers, but their more common models were often outstanding. The manual-wind movements such as the Omega 30mm and Longines 30L remain among the best ever produced, and especially so given their high-production numbers.
I generally prefer simple, understated designs, and only own one chronograph. I have, in recent years, developed a soft spot for (mostly) mid-range vintage dive watches, and that aspect of my collection has expanded rapidly. I have a fairly large group of chronometers, as well.
Part of what I enjoy the most about collecting is that there are so many interesting sub-genres to consider. I have become much more open-minded over the years, though still have high standards when it comes to condition. I now have quite a few examples from manufacturers that I once dismissed as being moderate, and it feels good to have discovered that many of the "lesser" brands actually designed some very nice watches and movements.
Longines is one of, if not my favorite brand. I have some Conquests, several individual models, and, of course, Flagships...