United is offering 20% off the redemption cost of coach bookings made between now and November 15th to Europe for travel dates between January 15th, 2013 and March 13, 2013. This brings the total for a US-Europe roundtrip to 48k miles from 60k miles. The offer is restricted to United-operated flights and applicable to one-way tickets.
American’s off-peak period to Europe runs between October 15th and May 15th annually, bringing the total mileage cost down from 30k miles for a coach one-way to 20k miles. Rather usefully, the off-peak price is applicable to British Airways-operated flights as well. BA flights still carry the customary British Airways fuel surcharges, so an “award” with BA transatlantic segments could easily run as much as an outright revenue ticket.
US Airways offers its own off-peak awards for US Airways metal for itineraries between January 15th and February 28th. In addition to their discount coach roundtrips for 35k miles, US Airways offers business class roundtrips for 60k miles. While coach inventory seems plentiful, business class is a bit more disappointing: