Oh, I saw your other post that you can not fly United. Oh well.

Delta flights to ATL and DTW look great up front but I can not remember if OAL get put up front or not. The flights from ATL and DTW to IAH look OK.

Also, if you were able to do US airways the flights to IAH from CLT or PHL are wide open but the FRA flights are booked-but you could hope for no shows, booking errors etc.