As the second major airline allinace to be formed (1999), Oneworld has 15 member airlines (note that Aer Lingus is expected to Join Oneworld in the near future) covering over 1,000 destinations in 155 countries.
Though it's the smallest Alliance, Oneworld can get you anywhere in the world in style. British Airways has a great first class product (kind of like Business++ compared to suites and such, but still solid) and is an Amex MR redemption partner, which means you can ultimately end up on BA, AA, and Qantas with Amex points (Qantas also works with Citi ThankYou), or transfer from Citi or Amex to Cathay which has one of the best non-suites first class products in the world.
