What are the essential watch “categories”?

[NachoNeal]

Daily casual (sub)
Daily dress (DJ)
Beater (skx and Hamilton)

[CedCraig]

These are my categories, not that I‘m aiming to fulfill them all.

-Movement:
1. Mechanical, self-winding
2. Mechanical, hand-wound
3. Quartz
4. In-house
5. Old standby: like ETA 2824-2
6. Other: high beat, co-axial, spring drive, dual impulse

-Age:
7. Modern
8. Vintage

-Style:
9. Sports
10. Dress
11. Nice beater
12. True beater
13. Smart

-Material:
14. Stainless Steel
15. Titanium
16. Precious metal

-Country of origin:
17. Switzerland
18. Germany
19. Japan

20. Complication beyond date and day

-Dial color:
21. Black
22. Not black

-Brands
23. Major
24. Independent
25. Something from The Crown family
26. Higher Horology

[Ichiran]

Only 2 categories - dress watch (DD and DJ are not) and others.

[MrEleven]

If your going to own a few different watches i would say must haves are.

1. Dive watch, mines ap diver
2. Chrono, mines omega speedy pro
3. Gmt, mines rolex gmt 50th anniversary
4. Beater, mines g shock

I have my 4 and the 5th for me is a simple 3 hander that will be a patek aquanaut