A couple years ago I bought my son a custom 3d printed miniature for his Dungeons & Dragons character from Hero Forge. Hero Forge has a very nice interface for customizing a miniature with various features, and then Shapeways does the actual 3D printing.
Hero Forge recently launched a Kickstarter campaign to raise money to allow it to begin doing custom 3D miniatures in color. So far it has raised more than $2 million in a little over two weeks.