Since US Airways joined the oneworld Alliance on March 31, I think they have the most valuable miles of any airline. The three main reasons:

The world's cheapest award chart.

TAM, the largest airline in Brazil, joined oneworld today March 31, 2014.

 

The oneworld roster with the addition of TAM.

You can now book a one way flight from the United States to Brazil for 4,000 Avios and $97.50!

TAM flights are bookable with American Airlines miles and British Airways Avios and searchable on ba.com. American Airlines and British Airways do not collect fuel surcharges on TAM flights.

TAM has flights between Brazil and New York-JFK, Miami, and Orlando. All three American cities have flights to Rio de Janeiro–Galeão and São Paulo–Guarulhos.

On February 1, United miles became much less valuable for premium cabin flights.

Not only did all first class awards outside of the western hemisphere go way up in price, but partner first class awards went way, way up.

Since people who want to fly first class awards want the swankiest, most aspirational flights, the increase in the partner award price is a big problem.

United Global First is good.

For flights between the US and Europe, Austrian Airlines releases its economy class award seats to partners 298 days before the flight and its business class award seats to partners 88 days before the flight.

Austrian routes between the US and Europe have economy award space up to 298 days out

Austrian is a Star Alliance member that operates five routes to North America from its hub in Vienna:

New York-JFK
Chicago
Washington-Dulles
Toronto (don't forget about routing to Europe via Canada)
Newark (begins July 2, 2014)

Austrian operates two cabin Boeing 777s and 767s

There is:

widely available
underpriced
economy award space
for two passengers
for all of 2014
to Australia
with the opportunity to stop in Hawaii for a few days in either direction.

If you have 75,000 American Airlines miles and about $100, you can fly a roundtrip award from the United States to Australia on almost any day you want this year.

Buried in Delta's major award chart devaluation last year was a second piece of bad news: Delta awards could no longer be put on hold under any circumstances.

But there had to be a way, I thought.

In Part 1, I shared my experiences at the 2012 Euro Cup and how they informed my plan for the World Cup. I also discussed the flight and hotel awards I booked for myself.

Did you miss 20k Miles (or Less) to All of South America All Year yesterday? That post is a competing trick with this one, and it might be an even better deal for you.

Chicago to Santiago "should" cost 30,000 American Airlines miles each way in economy.

Or: Save 10k Miles by Adding a Free Oneway

Summer airfare--during our summer or theirs--to Southern South America usually tops $1,000 per person in economy.

But you can get to South America this summer for only 20k American Airlines miles one way.

All the legacy carriers--Delta, United, American, and US Airways--charge 60k miles roundtrip on Saver economy awards to Southern South America, which includes Brazil, Argentina, Chile, Bolivia, and Paraguay.

American and United let you go one way for half the price while US Airways and Delta charge 60k miles for one ways.

American is even more generous with

Update 12/17/13: The 50k mile offer on the Lufthansa card is dead.