After four decades and over 200 watches that I've owned and flipped onto others and making the same mistakes over and over again, I am a watch nut afterall! I can say that I don't believe one needs certain watches in the collection or use a pattern that many claim would make a "complete" watch collection in the WatchBox such as casual, dress, diver, tool, sport, pilot, chronograph, Tourbillon, master complication etc. Today I look for design, materials, workmanship, size, proportion, comfort, these are key important characteristics for long term relationship in my view, along with of course the manucture brand and I appreciate more than ever "in house" manufacturing to insure no cutting corners like when ETA announced in 2004 no more movements for the majority of the watch industry and everyone went into panic. Finally as operating engineer of mechanical systems and operation I love watches that are purposeful as well functional past or present like divers, sport, tool/utility, pilot, casual and the like, also my favorite complication are chronograph, true GMT, big date, power reserve and others. Watch manufacture I love for years are Glashutte, Breitling, Omega, Seiko, Rolex, Tag Heuer since a youngster, Longines, Zenith, Blancpain, Corum, IWC and a few others that have history and progressed over the years.