Nordstrom is, unsurprisingly, always a solid one-stop-shop. It carries a large variety of top brands, including some very popular startups, and has a few major sales events, a good rewards program, and a great customer service department. The site will also put together styling suggestions which is helpful for figuring out what goes with what.
Nordstrom has a vast selection of professional work styles, and we don't use the word "vast" lightly. Expect to find everything from business casual to designer formal business suits, any of which can be found anywhere along spectrum of price points at Nordstrom; from budget friendly to ungodly expensive.
We grew up with Nordstrom, and over the years it's gone from your usual department store to something so much more (and cooler!). Under the creative direction of Olivia Kim, they also have curated pop-up shops promoting newbie designers and indie home goods.