Lufthansa: Often the preferred carrier for BOS→MUC because of hub strength (FRA/MUC) and potential nonstop service. Pros: strong European network, good business class and lounge access; cons: higher fares during peak December travel. United/Delta/American: Offer one-stop options via partner hubs (e.g., Newark, Chicago, London) that can be competitive on price and schedule; pros: frequent flights and loyalty program integrations; cons: longer travel time if connecting. Icelandair or other carriers offering transatlantic connections can be attractive for budget-conscious travelers using short stopovers. When comparing, evaluate nonstop availability, total travel time, baggage allowances, and alliance benefits; book early for preferred cabin and winter schedule security.