LAX/EZE - Lan is choice 1. I know this is a UA forum question, but if you get the nonstop LAX/SCL day of travel (and note that this can change without warning, as it did on the trip I'm currently on), LAX/SCL is a pleasant flight, and SCL/EZE is a piece of cake - the SCL connection is a breeze, and is the only 1st world airport in the LAX/SCL/EZE routing. If you get in a bit early to SCL, you will have time for a shower in the lounge and arrive @ EZE, fresh as a summer's eve. I have flown this routing since Dec 2007 6 times (sometimes stopping over in Chile, sometimes not) and haven't had a delay of more than a few minutes on any segment this past year. Also, if you like your wines, Lan is your best choice.