I've watched it for my whole life, but only a couple of years ago I realised that Thunderbird 1 goes down the ramp into the launch bay with the name on the fuselage facing the camera, but a second shot from the side show sits still readable...since when did TB1 swivel 90 degrees?.
I often delight in asking Star Trek: The Next Generation newbies did they spot the 'little figures' in the opening credits?.
After Brent Spiner's name appears, keep focused on the conference lounge windows on the top 'bubble' of the saucer section as the ship moves under the camera.
A tiny figure moves left to right, gives you a realisation of how big the ship is!.
The "little figure" sometimes noticed in the Star Trek: The Next Generation (TNG) opening credits is a piece of hand-drawn animation used to create the illusion of crew members walking inside the Enterprise-D's conference lounge.
There are also tiny visual gags 'Okudagrams' named after the shows graphic artists, Mike & Denise Okuda, in the large 1701D graphic in engineering : a duck, a mouse, a Porsche, a DC-3 plane, the Nomad space probe (TOS episode 'Changeling') and a hamster in a wheel are hidden in various rooms/shuttle bays.