Christmas Day 1989, I'd had a brief week in The Gambia. Old BCal route on DC-10, a daylight with early start. The flight was not busy and flight deck PA said to keep an eye out for the beach after departure.
The inbound crew, who landed a couple of hours earlier, were waving from the beach as we dipped across. Some might have thought that our drivers applied more thrust than was needed when pulling up, up and away. I thought it a very sensible use of fuel. A great party atmosphere sector and an open invitation to visit the sharp end.

That's interesting, I live by Feltham and I would segment this way from loud to quiet.
Impressively loud : B744 mostly gone now
Loudish : Long distance A330 / B777
Noticeably quieter : A380
Impressively background : B787 / A350

The latter two are incredibly impressive in how quiet they are.

You'll notice that those rankings exactly mirror their entry into service (i.e. certification) dates. I'd add that the 747-8/8F is similarly quiet to the 787/A350. I was literally shocked the first time I watched a 747-8F takeoff up close (as in less than 100 meters from the runway) at how quiet it was.
The 747 Large Cargo Freighter (aka 'Dreamlifter') is even worse than the 747-400. While I'm disappointed that the 787 final assembly is moving away from Everett, at least it means I won't be hearing the LCF on a regular basis...

I live in West Hertfordshire and (weather/time of day depending) am under LHR, LTN and STN. I also sometimes hear LGW traffic northbound. The deciding factor is often wind. On a quiet night I have heard something distinctly, checked and found is a North America origin heading to CDG/FRA or beyond. They might be at 40,000 but I can hear them.

The LHR departures going North East are at 6/7/8,000 but I have not kept notes of which is noiser. Granted the Queen is still distinctive but I would go with the age of introduction. Some of the A300 freighters to LTN are noiser without a doubt.

Flying from AKL to SYD back in 1983 on a Qantas 747SP, probably way less than half full. Pilot said 2 boys in a dinghy had gone missing in the bay so we would be flying low to keep a look out for them, and asked us all to keep a look out. All I can remember thinking was that Search and Rescue in a 747 was just wrong.

Flew for ages with mountains either side of us, skimming the water below.

At least, that's what it felt like after 8 weeks following the Lions !
( heard before we landed that they were found safely)

Ain't no mountains that close to either Auckland or Sydney. :E

For somebody who had never been in a 747 before it was an interesting start.
Ok, maybe I should have said hills and not mountains, but it was just a light hearted comment.

BTW, we weren't skimming the water either ;)