Qantas: 6,000 Miles to cancel, 5,000 for changes
ElAl: $60 for non PL $10 for PL members
ANA: Allows free date changes, Cancellation results in a 3,000 mile penalty.
Aegean: 20 Euros
Aeroplan: There is a C$100 charge to change or cancel, within 21 days of departure C$250 charge to cancel
Singapore: $50 change fee, $75 cancellation fee
United: outside of 61 days $75, within 60 days of a flight $125
Miles & More: $60 charge to change or cancel
AA: AA allows free date and routing changes, but changes to the origin or destination city or cancellation costs $150 for non-elites. If you cancel more than 1 ticket at a time the fee is just $25 after the $150 fee for the first ticket
BA Avios: $55 or the taxes you paid, whichever is less. Domestic fares are only $5.60 to cancel.
JAL: Free date changes. Other changes or cancellation results in a $25 penalty
LAN: Changes are $75 or $150 within 21 days. Cancellation is $125 or $300 within 21 days
Alaska: $125
Alitalia: Date changes are free, other changes incur a 5,000 mile or 55 Euro penalty, Cancellation is not allowed
Delta: There is a $150 charge to change or cancel an award ticket. No changes or cancellations are allowed within 3 days of the flight
Air France/KLM: 45 Euros