I always loved shopping, even when I was heavy. Admittedly, I never quite made it to the plus size shops, I shopped at "regular" stores that carried up to size 16 or 18, and 16s were a tight squeeze at my heaviest. When I was that heavy I would get depressed while shopping because there were so many cute clothes that just didn't come big enough, so I shopped for other things instead -- shampoos, body lotions, stuff like that.
I was in grad school while I was losing and had basically no money, so any new clothes I bought came almost exclusively from the Old Navy clearance rack. As my old clothes got too big I packed them away into big trash bags and eventually dropped them at a donation center. Most of my current wardrobe was purchased more than six months after I hit goal -- when I started my current job and had real money.

Now I get my clothes mostly from the Ann Taylor Loft sale racks (I find it so hard to pay full price for anything!).
What do I have left over from before? Some clothes I had kept from high school for unknown reasons that suddenly fit again, a bunch of shoes, some jackets and coats, and a couple dresses and skirts that I keep saying I'll have altered but never get around to it. And a bunch of spandex-y t-shirts that still fit since they were so stretchy that they had just stretched out to contain my fat.
As for style . . . I never really changed in terms of my taste. I never was really into wearing big baggy clothes -- I was one of those fat chicks who squeezed herself into the tiniest size possible to try to convince myself I wasn't as fat as I was. :P What has changed recently is that I catch myself at the store saying "That's cute, but it would never look good on me." I challenge myself to try on those clothes whenever I hear myself saying that, and you know what? Some of them do look good on me after all! Who knew?
Come to think of it, I actually wear slightly less revealing clothes now, at least in terms of cleavage. I don't think this has too much to do with fat vs thin as it does with teenager/college student vs. young professional.