Etsy.com - Etsy is the king of handmade. With upwards of 400,000 sellers on Etsy you can find everything from homemade teas to a wedding dress. If you're looking for something specific, searching Etsy can be a tedious task; a search for "clock" turned up 10,079 results. Etsy is also home to barrage of crafters. Anyone with a sewing machine or glue gun can post on in the marketplace, which can lead to some pretty interesting (and creepy!) items. Check the Regretsy blog to see what I mean. While I support anyone looking to share their creativity, it can often be hard to sort through all the hobbyists to find the top quality product you're looking for. Many Etsy sellers also sell on the marketplaces below.
1000Markets.com - 1000 Markets is a step above Artfire. Though basic, the website design is decent. Again, most of the sellers are hobbyists and start-up crafters but there are a lot of neat products. One thing I'd do is change the layout of the categories. Right now, only four are featured on the front page...you have to click "see more" to find the category you're looking for.
Supermarket - I've blogged about Supermarket before. Like MakersMarket, Supermarket is a curated selection of products. In my book, Supermarket is the best of all the online artisan markets. There are only a select few designers available and there aren't many bells and whistles on the website, still it's pleasing to the eye and you almost always find what you're looking for. Expect some products to be a little more expensive than the other sites since you're working with more serious designers/crafters.