We just came back from a trip to Berlin to see my wife's cousins and also for the Christian Science Annual Meeting.
Berlin is a shopper's smorgasborg, a history lesson, a garden, a big city and an architectural (ugh, sp!) and musical treasure all at the same time (despite the world's ugliest TV tower.) The Checkpoint Charlie Museum is a required visit, and if you don't leave it with tears in your eyes, then you have a heart of stone.
The two of us are lucky to have friends and cousins who have access to the freshest meat and wurst, so we feel that we can comment on the cafés you can eat at on practically every block in Berlin.
First of all, we did not encounter a single instance of anti-Americanism if anyone's worried about that.
In general, we found the service slow, probably because the cost of running a restaurant in Berlin has forced most owners to cut down on staff. So be patient!
The places we ate were in three areas: "Mitte", "AlexanderPlatz" and between Lutlowplatz and the "Zoologischer Garten".
I'd say that if your German is good to try anything. Be aware that smoking is more common in Germany than in the U.S. You will need to be careful to have plenty of liquids wherever you choose to stay because if you are non-drinkers (like us), you will need them. The Italian restaurant we ate at was very good. One street café was OK with only average wurst, but again as we mentioned above, we are spoiled. Another was excellent. Some of the restaurants we saw were truly fancy - and unaffordable (for us).
I'm not sure if recommending restaurants in Berlin is the best idea, particularly in terms of the true Chowhounder, and here are the three reasons why:
1.) Berlin, more than any big city (or even small city) we have seen is changing EVERY day. A restaurant I might recommend could be gone (or replaced by a brand new better one) the next day!
2.) Drinking tastes (especially for beer drinkers!) need to be thought about carefully because restaurants are staunch allies of the beer they serve.
3.) It's very tough to find a bad restaurant in Berlin due to the highly competitive situation there, especially now.
So if you're thinking of going to Berlin, go! Go unafraid. The city is cool, safe and intensely interesting.