The Space Shuttle is considered to be the spacecraft with the gentlest decent and landing. I was surprised to learn that its ascent was quite a rough experience.
So I was wondering: Which orbital manned spacecraft, past or present, gave/gives the most pleasant start and ascent? From what I've read so far, Falcon 9 with Crew Dragon might be a candidate.
The two solid boosters give a rough ride at best and a bone-jarring experience at worst. The grain effect of the solid propellant mix gives a rough ride, where the eyes find it hard to focus and the general sensation is of riding at relatively high speed over a road of broken cobbles in a vehicle without any form of suspension. Added to which, the flexing and twisting of the Shuttle's motion, as the engines gimbal to keep the vehicle on course in bumpy air streams and high wind, is a combination most astronauts find unique and quite difficult to forget!
(From NASA Space Shuttle Owners' Workshop Manual by Dr. David Baker.)
It seems you already get a good kick when the SRBs start, with a thrust-to-weight ratio of 1.7:1 on start.
The Saturn V also seems to have been a rough ride, at least with the first stage, pulling up to 4.5G:
Shake, rattle, and roll! Noise, yes, lots of it, but mostly motion, as we are thrown left and right against our straps in spasmodic little jerks. … The G load builds slowly past 4, but no higher; unlike the Titan, the Saturn is a gentleman and will not plaster us into our couches. … [Staging] We are jerked forward against our straps, then lowered gently again as the second stage begins its journey.
(Michael Collins in Carrying The Fire about the Apollo 11 launch.)
In a minute and a half, we were pulling four and a half Gs. The thrill as marred by the onset of the so-called pogo motion, which shook us up and down, as if the gods where mixing martinis. … We had anticipated the same sort of staging jolt as on our Gemini flights, but this shutdown was unusually violent and we were thrown back and forth against our straps as hard as if we were hitting a wall.
(Gene Cernan in The Last Man On The Moon about the Apollo 10 launch.)
Also seems to reach 4.5G, but apparently not as much shaking and vibrating.
The Crew Dragon astronauts said the ride on the Falcon 9 rocket was smoother than the space shuttle for the first couple of minutes. … [After staging] “So little bit of vibration, not anything that was really unpleasant, but you certainly knew that there was powerful engine behind you,” he said. “And that took us all the way to orbit about six minutes later, and once again the Gs (built up), and how the engine throttled to control the Gs, and the engine cutoff.”