Moving my stuff from Germany to San Francisco

I am going to relocate from Munich to San Francisco soon. Has anyone here a good advice on what is the most efficient way of moving my stuff. I don't have many things but the airlines can only allow 23 kg of baggage to the US now.

There are lots of options: excess baggage on the flight, DHL... Can anyone recommend a specialized company for handling these things?

Thanks in advance!

Daniel