TAM (F100s) - Nice all-coach cabins with leather seats, and very good inflight service. Airplanes looked well-maintained. Safety practices worried me a little. On all flights, the seat-belt sign went off literally the minute the wheels left the ground, and everyone decided to go for a stroll. Nobody ever sat down even when we went through some rough turbulence over the Andes, nor did the flight attendants stop service. I was just waiting for something (or someone) to go airborne.
LAN Chile (737) - One of my favorites. Nice all-coach 737 cabins with modern, seats, full meal service on our short (2-hr) flight. Safety practices seemed on a par with North American carriers.
Varig (737, MD-11) - Far and away my favorite. Excellent service throughout, one of the few times I've actually turned down more food! Like LAN, safety practices seemed identical to U.S. Friendly, professional crews, and plenty of Guarana (Brazilian soft drink..yum!)
Lloyd Aereo Boliviano -LAB (727-200) - Ugh! I doubt the airplane I was on even still exists! Each row of seats was a different design, but I recognized seat covers from Continental and Northwest on there. First class seats looked like they had purple sheets over them! The crew was very nice, though, but I don't remember the meal service since it was three years ago. I was more concerned with landing in one piece anyway.