I think it's very complex to choose just one as a favorite website, but if I had to pick one this would be www.behance.net. Behance is a social network in which various creative professionals around the world, from different areas such as illustration, graphic design, photography and many others, upload their work to share with the rest of the world. Behance works as an online portfolio which is seen by many companies that could be interested in your work.
I use behance since I started studying design in 2008, at that time I discovered it as a tool to look references for different projects.
I like behance because it is easy to use, the navigation through the website is comfortable and each day you can see the work of really talented people from around the world.
Nowadays I'm using behance to check all kinds of work and inspire me to develop my own projects, I'm currently using behance to check all kinds of work and inspire me to develop my own projects, last year I create an account to upload my work to the website and to show the work that I have developed in the last time, but I left a little aside my portfolio you can visit in http://www.behance.net/PedroAlfonso, enjoy!
