If you are purely maximizing the miles, I would replace BKK with KUL, RJ has a 1 stop direct flight there some days of the week so it's just one segment, then JL KUL-NRT. Should add just under 1000 miles there. I would say, incorporating Gardyloo's valuable suggestions AMM-KUL-NRT-CGK-HKG-JFK-EZE-LIM-IPC-SCL-DFW-ANC-DFW-MAD-TLV-LHR-MCT, should be 57,665 miles or so. Just remember to make sure you spend less than 24 hours in JFK. Also, I know the LIM-IPC flight is seasonal (doesn't start until February 2012 and I'm not sure how long it lasts off the top of my head), so you can go LIM-GRU-SCL if needed, lose about 1000 miles but much more availability. The routing I have also saves the cost of the visa for Brazil, and the Chilean reciprocity fee is only taken for international arrivals in SCL from what I've read, so you wouldn't get hit with it in IPC or SCL (IPC-SCL being a domestic flight). Of course, neither of those may be a concern for you, particularly if you planned to transit GRU only or already have the visa. Good luck!