Love creativity? Design? Art? Then don't forget these....

Dribbble

Show and tell for designers or those who love design. Perfect if your niche has any affinity with design, designers or those who love design

https://dribbble.com/

Colourlovers

COLOURlovers is a creative community where people from around the world create
and share colours, palletes and patterns. Yes truly you can create a color and name it...fabulous. Plus create communities, blog and share links. Not to be missed.

http://www.colourlovers.com/

DeviantArt

Awesome social networking site for lovers of Art and Artists....grow your followers,create a gallery, share your thoughts and mussings...perfect for niche specific sites

http://www.deviantart.com/

Behance

Create, view and share online portfolios and grow your network. Photography, art, web design - in fact any kind of image or design sharing is welcomed and can send your links viral

https://www.behance.net/