Amsterdam. Tremendously walkable, green spaces everywhere, canals are cozy, and isn't nearly as scarily white as some cities on the continent can be. It's got all the buzz of a big city without a lot of the drawbacks. That said, I'd love to visit Paris as the last few years have seen it make serious strides towards walkability, and it maintains a multi-ethnic vibe with bomb food.

EDIT: Also weirdly Sarajevo. Very cozy place, although I'm not sure I'd live there.