Train from Paris to Munich

SNCF and Bahn.de are your best source and provide the best prices. Those are the national rail systems for France and Germany, respectively. Prices can vary, depending upon the time of day, number of connections, speed of the train, etc. Either site would be perfectly acceptable for buying tickets. Just choose whichever one offers the best price for your schedule. FYI, if you buy from SNCF, having the tickets shipped to the US is not an option. You can either print the tickets yourself or pick them up at a station in France. SNCF is part of RailEurope, which sells the same tickets at (usually) higher prices. Hence, SNCF tries to force North American customers to buy from RailEurope.