AA actually has many 757 Brazil flights that fly all night down but fly a day trip back. Recife, Salvador, Brasilia, and Asuncion. Leave around 2300 arrive 0800... Return leaves around 0900 and arrives around 1700. Pretty decent from what I'm told. Best of all, it's a 3 man operation on the flights down but the IRO deadheads back on the return.
I also think AA flies a couple of daytime 777s to Buenos Aires and Sao Paolo.
Sweetest trip on the 777 (if you're local to New York) is the morning JFK-LHR. Leaves at 0900, arrives 1900. Return leaves LHR around 1700 and lands jfk around 2000. Talk about staying on your body clock! Super senior trip.