I‘ve lived in Munich for the last seven years, and have run through a fair share of cards. „Best“ is a somewhat subjective evaluation, since it all depends what you‘re going to spend you money on.
As you‘ll see when you get here, the credit card rewards programs in Europe are very poor, since most Europeans outside of UK don‘t carry debt on their credit cards, as such the credit cards (at least in Germany) act more like charge cards than credit cards. You won’t get any rewards, and you also won’t have any benefits (loss protection, etc). You‘ll also need a local bank account regardless of where you end up, since you need to pay for rent, electricity and such in the local currency. Most countries in Europe also have a locally issued debit card that runs on a parallel network than Visa/MC/AX.
Overall, you probably won‘t go wrong with the CSR, my favorite everyday card here is the BofA premium rewards card ($100/year, with $100 US airline incidental credit), which with preferred status will get you 1.5% + 175% bonus = 2.625% on all purchases, and 2% + 175% = 3.5% bonus on dining and travel. You‘ll be hard pressed to find any other card that matches this. If you will be doing a lot of travel however, the benefits offered by Chase (delayed baggage, interruption, cancelation) premium cards is better than BofA‘s.