Berlin is fairly different from any US city. The public transportation is much better than any I’ve experienced in the us; it is kept extremely clean and is always on time. Additionally, with a single bus ticket purchase, the ride is completely hassle-free. I wish the US had transportation like this.
I did not expect to never see any drinking fountains anywhere. In US schools, there are drinking fountains seemingly everywhere but even in the Mensa there is only 1 for filling water bottles.
The city itself seems to be built much more outward instead of a couple large skyscrapers like US cities. Pollution control seems to be much higher here than in the us. There are garbage cans everywhere, and there are always street-sweepers driving around.
I wish that German food was more common back home, since I like it more than common American food.