RLymburner asked this question on the "all time best" thread, but it got lost. I, and I am sure others, would like help in discovering current opportunities we may be missing. On the other thread I nominated:

TD WATERHOUSE. 10,000 AA miles for a $10,000 new deposit of money or securities, or 25,000 AA miles for a $50,000 deposit.

SAVINGS BONDS DIRECT. Using a miles-earning credit card one can get better than Money Market rates.