Well I would recommend if you are flying a Star Alliance to put the points to TAM although they expire in 2 years it is only 60K to redeem a round-trip on the low season... BR-EUROPE, I would recommend TAM if you usually get CC miles on a Card that you can transfer, so you join Flight+Card, and should help you get miles faster. Plus, TAM Plat Card gets you some perks when flying with them.

ANA is also great!, Pay attention only that the free flight must be for you or your immediate family, you cannot redeem a free flight under any name. This case you might need only 55K any season to get BR-Euro, and their mileage lasts for 3 years, one more than TAM.

If you want to keep using One World, wich I don't recommend, would be BA Program. The problem about using AA or LAN is that they account only 30% of the miles on lower fares...

Hope that I gave you some ideas,