I could never narrow it down to one pair of shoes, but if I want to pick a "most indispensable" for each seasonal shift, here are my must-haves:
1. winter: the Ugg Cortonas. They convert from very simple Chelsea boots to tall boots with the addition of the spats. Super comfortable and warm and versatile.
2. summer: the LD Tuttle Freeze sandals. These were a game-changer for my summer style. I balked at the price for sandals, but they were well worth it for quality and style. I wanted something to edge up simple summer outfits, and these are it. Comfortable and versatile, and they work with dresses, capris, shorts, rolled jeans/pants...
3. fall or spring, but also into summer and into not-too-cold winter days with socks: Jeffrey Campbell woven Everly booties. I bought these on a whim and then wondered what on earth I wore before I got them. Again, comfort and versatility make these workhorses -- I can wear them with jeans, skirts, even shorts.
I definitely have a desire for distinctive footwear, so I'm willing to pay a bit more to get something that you don't see EVERYONE wearing. I'm reaching for heels above 3" less and less these days, and all of these fall into the category of easily walkable shoes for me. I also wear a fair amount of black, so it's easy for me to default to black shoes. I would actually love to get a new dark grey/gunmetal metallic pair of booties -- I used to wear the sparkly Rag & Bone Newburys a lot, but now they're feeling too high for all-day wear, and I mostly reserve them for short wears or an evening out.
My most recent shoe purchase is the blue Chloe Modern Vice booties. These tick all my boxes too, for comfort and versatility, while adding some extra style to my winter footwear:
http://www.modernvice.com/coll.....e-stingray