British Airways and American Airlines have round trip airfares travelling from San Francisco (SFO) to Berlin Germany (TXL) for $523, making 1 stop in London.
Departs SFO: Sept 26; Oct 9-10, 15-17, 27, 31; Nov 5-8, 10-11
Returns: wide and good availability returns, generally 7 days
Use dates and book it on British Airways [britishairways.com]
or American Airlines [aa.com]
. For hotels, check out Hotwire's [hotwire.com]