You can earn triple Cathay Pacific AsiaMiles (August 1 – September 30) when flying from LA or San Francisco to Hong Kong on first, business, or qualifying (Y, B, H, K, L, M, V) coach fares.
You could also choose to earn double American AAdvantage miles through August 31 on these flights, but only when flying first or business class (“I” business fares are not eligible for the AA offer).
Personally I’d opt for the AsiaMiles, both because coach fares are eligible and because AsiaMiles are hugely valuable — they allow upgrade redemption on Cathay, American, and British Airways and 60,000 AsiaMiles gets you a business class award on BA from the US East Coast to most destinations in Europe (it would take 100,000 BA miles).