I've had many many good ones. Two come to mind -
First flight - BOAC Stratocruiser "Canopus", only six but learned what "engine run-up" meant big time.Routing, if I remember correctly was Ringway-Prestwick-Shannon (everyone got off and had a big meal in the terminal)-Gander-Dorval.
A little later in life: A320, Calgary - Vancouver - jump seat.
An hours flight, an hour and a half before sunset,cavu, over the Rockies.
Does not get much better than that.