MEGA DEAL: The Oneworld Alliance offers some insane business class prices for flights from Berlin-Tegel to San Francisco! For just 1,327€ you can get to California and back this Winter, which is especially awesome knowing the normally high prices from Berlin.
You can choose from multiple Oneworld member airlines, whichever you prefer for the long transatlantic segment (e.g. Finnair, British Airways or Iberia). I personally prefer Finnair’s Business Class due to its layout and service, so that’s my recommendation.
The cheap flights are offered in November and December 2019, which allows an awesome winter trip or even Christmas holiday. The following Google Flights screenshot shows some examples of available dates: