Art.net
www.art.net
Art.net is an online gallery promoting artists from around the world. The site is very basic in design but there is alot of good art displayed on Art.net.
Artists and catagorised by genre and each artist has their own page with their own design and layout which makes the site a bit different to most art sites.
Art.net has been running since 1994 so it is a well established community. If you are an artist you can also apply to have you art displayed, there is a membership fee of $60 they also require that new artists donate one piece of their artwork upon joining!