The Web is full of great online shops. eBay is the garage sale of the universe. Amazon is a giant department store. And there are tons of focused shopping sites, selling everything from underwear to auto parts. But for the most part, they're all old-school.
If you want a more contemporary shopping experience, try Etsy, a marketplace for handmade goods. Like many of the items that Etsy artists sell on the site, Etsy itself has been crafted with care, love, and a whacked-out esthetic. Heavily Flash-based, it has unique and fun views into the goods available. For example, there's a "shop by color" function that does just what you'd think (although not all that accurately). The cool thing is that the thumbnail images it displays can be dragged around the screen (which helps you compare items), or even thrown off the screen entirely. There's a similar Flash-based shop-by-location feature, a random item view, and also a hypnotic shop-by-time-added function.
The site pushes the current state of the art in commerce and interactivity. Soon to come on Etsy are social shopping features that will let you browse online in real-time with your friends -- you'll be able to see their cursors on your screen alongside yours. Useful? I don't know. But if the feature is as well-crafted as the other lenses into the Etsy store, it will be a lot of fun.
I like founder Robert Kalin's philosophy: "We're throwing things out there that aren't 100% useful, but they get people to use the site." It's like good recreational shopping in the physical world - an experience that's about more than just finding and spending.