The best credit card sign-up offer out there is once again available for a limited time (the offer seems to come and go). You can apply here. You earn 50,000 British Airways miles after your first purchase, and 50,000 more miles after spending $2,000 on the card within three months. As Gary points out, this card can be especially lucrative thanks to the ability to “pool” accounts in the same household, along with the free companion certificate for spending $30,000.
(Tip of the hat to Frugal Travel Guy)