Paris has dozens of restaurants which are better than any in Berlin, and then hundreds more better than the rest. Yet it may be the case that you have, overall, a better food life in Berlin than in Paris.
Berlin has a weak reputation among foodies, but culinary life in the city is much improved. Here are my tips for a good eating life in Berlin:
1. Find a steady source of innovative rolls, buns, and dark breads. These are the glories of Berlin and in many parts of town there will be at least one such source per residential block. The more irregular the colors, seeds, and topologies of the breads, the more enthusiastically you should buy them. Do not treat this as the French bread buying experience.
2. Find a source for good spreads, such as cherry, raspberry, etc. and stock up. Repeatedly apply the spreads to the breads, until death of the researcher intervenes. This procedure is the basis for everything else you will do. It ensures that all of your food days will be good ones.
3. Seek out mid-level German restaurants, of the kind promoted in the Time Out Guide; Renger-Patzsch is a good example. The vegetables in such places will be consistently excellent.
4. The speed and service quality of most meals will be much better if you arrive before 7 p.m.
5. Don't obsess over German food. It's underrated, but still a lot of it isn't that good. In Berlin, and many other parts of Germany, you have first-class delicatessens or stores with foodstuffs from France, Italy, and many other parts of the world. Use them. Berlin offers one of the best overall selections in this regard, better than New York City or Paris, for instance, in terms of real access. You can eat first-rate French cheese every day.
6. When it comes to Berlin German food, don't eat anything in a sauce. It will be either boring or disgusting. Sorry.
7. The sausage spread at the KaDeWe (make sure you live near that place) is probably the best in the entire world. Go there regularly. They also have first-rate sausages from France, Spain, and other countries, as well as an unparalleled selection of sausages from the different regions of Germany, organized one region per case. This food source, like #1, insures that each of your food days will be a splendid one.
8. Go to Berlin's numerous and varied ethnic restaurants, especially in the slightly lower rent districts. If the food is supposed to be spicy, you must repeat the following incantation several times: "Ich will es essen, genau wie Sie es zu Hause essen. Ich bin kein deutscher." [I want to eat it exactly as you eat it at home. I am not a German."] Repeat especially that last part: "Ich bin kein deutscher." Repeat it even if you are a German. This will usually work and typically your Chinese or Thai or Indian server will smile and laugh in response. If they view you as a German, you are screwed no matter what. Simply asking for the food to be "spicy" or even "very spicy" is laughable. It is showing yourself to be a fool and a sucker.
9. Food here is much cheaper than in Paris, and it is much easier to get into virtually any restaurant. Take advantage of both features.
10. Italian food here is almost always reasonably good, and reasonably cheap, but it is rarely great. Lots of cream sauces. It's a good enough fall back and you find it virtually everywhere. A quite good pasta for $6 or even less is a common experience. Sometimes it's actually German food in disguise, or not in disguise, such as when you get Carpaccio with Pfifferlinge.
11. For ethnic food, I recommend the following: Tian Fu in Wilmersdorf (very good Sichuan), Suriya-Kanthi (Sri Lankan in Prenzlauer Berg), Genazvale (Georgian food in Charlottenburg), Degirman is one good Turkish place of many, a slew of authentic Mexican restaurants (more than in Virginia), DAO restaurant in Charlottenburg (Thai food, best papaya salad I've had, all-around excellent), and Schneeweiss has first-rate Wiener Schnitzel.
Overall Sri Lankan and Nepalese and East bloc cuisines are better here, or more available, than in the USA.
If you visit for one day, you won't be so impressed with culinary life in Berlin. If you stay for a month, you won't want to go back to what you had before.