I've been to Berlin a few times now both for school trips and for pleasure. It remains one of my favorite cities that I've thus far visited, and I'd love to live there some day. The atmosphere is one of contrast between old and new, past and present, clean and rough. There's always something going on.
Its unique history post-WWII has allowed Berlin to reinvent itself in ways uncommon to other cites that are overwhelmed by their image. It has become a hotspot for the young, for artists, for immigrants, for foodies, for politicians, and for techies alike.