i refer to Facehunter, for an arty, Euro approach and check the Satorialist regularly to see what the rich & high-end are rocking. lookbook.nu is quite popular these days too and offers an "everyman's" approach to styling.
However, my go to site that is somehow both inspired and down-to-earth is Style Arena. As we all know, the world is generally gaga for the Japanese aesthetic. Jeremy Scott hearts Shibuya, as does Opening Ceremony. Maybe it's their playfulness, maybe it's their obscene disposable income - don't know - but the Japanese sure know how to put it all together. Style Arena is so much fun for ideas and references - specifically the art of layering! It is updated weekly and archived beautifully. The best thing about this site is that you can look at outfits by neighborhood. personally, i'm drawn to the polished, trophy-wife look of Ginza ladies. what about you?

photo, Style Arena, Feb. 2010