Best takeoff: Rocket launch in a 767-300ER off 34R at Sydney for Canberra with only about 70 people on board and probably a hugely derated takeoff too! Check out airliners.net for the visual proof
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Best landing: Jumpseat on QF11 into LAX in 2001. I remember the pilots saying "Southwest 737s are like blowflies around here", seeing Long Beach airport, being alarmed at the water dripping down from the ceilling, and the F/O saying "Buuueatiful!" to compliment the Captain's landing.