I've been on a 747 before (from Los Angeles to Amsterdam), and as much as I love the 747, that may be the worst plane I've ever flown on in terms of passenger experience. We had a seat right next to the engines. It was all I could manage to get to sleep (the seats were cramped and uncomfortable), and the roar of engines made it so you had to speak fairly loudly to talk to somebody right next to you. The 777 I flew on the way back, on the other hand, was great.