Both. Some people look good with pale complexion and some people look good with an olive/tan complexion. It really depends on the person. For me, I prefer having a pale complexion. I tried the tanning thing, it didn't work for me.
Some people simply cannot tan, so I wouldn't hold it against them for being pale. Tan is mostly aesthetically pleasing to the general public, but there is something admirable about someone comfortable in their own skin not to try to change it. Some people rock fair skin though, like the amazing Nicola Roberts.