I have bought several beautiful things from Etsy, none of it quilting related. One thing I like is you can put in something odd (like I searched "leafy seadragon" because my sister loves those things) and find beautiful handcrafted items (I found a hand thrown and painted mug with a leafy seadragon on it). I found some really nicely made car litter bags and matching tissue holders I bought and they are great. I bought a few as gifts. I have a friend who sells really pretty silver and beaded jewelry there too.
As far as most sewing stuff, I can do better making it myself, usually. I wouldn't go there for fabric etc unless I was looking for something special and hand dyed.