It seems like every season has some must have menswear items like topcoats in the winter or trench coats for the rainy season. In this area you can even throw in suits and ties due to the nature of your job. Similar to this are other items in workwear/streetwear that you have no use for such as work boots or chambray shirts.
My list:
Trench coat - I am an umbrella guy which is from my car to office building and back
Top coat - Similar reason as my car is garaged and I just walk into the office with a suit or sport coat with a scarf even today at 10* F
Work boots - I don't need 1000 mile boots or similar items. I like when items can pull double duty such as Dalton's or some similar dress cap toe boot
Pocket square - I end up with a poof every time and the only time I like them is in white
Barbour jacket - I feel I would let the brand down city dwelling in a Barbour though I may plunk down $50 for a waxed cotton hat though...
I am sure there are some other items but this topic came to mind after seeing threads mentioning needing a specific item and I can't help but think, "I would never use that."