Of crewed spacecraft, the space shuttle had the gentlest landing. No other crewed spacecraft had rubber tires, shock absorbers, and a "flare" at touchdown. (Mercury had an airbag.) The shuttle's maximum allowable vertical descent rate at touchdown was 2.75 meters per second, and this article suggests that the goal was closer to 1 m/s.
Soyuz descends at ~7 m/s under parachute, but a solid rocket fires at about 1 second prior to touchdown to further slow the capsule to 1.5 m/s -- but the touchdown rocket itself is a bit of a jolt, and there's no landing gear to absorb the impact force.
Apollo splashed down at 10 m/s if all three parachutes were functioning normally. Apollo 15 came down a little faster as one of its parachutes was fouled. The capsule hung from the chutes at a slight angle, to help spread the impact force over time by hitting on an edge instead of "belly-flopping" on the broad heat shield. The nature of splashdown led to some variability in crew comfort; Apollo 12 hit a rising wave on splashdown and a camera was jolted out of its mount, concussing lunar module pilot Alan Bean.
Gemini and Mercury were somewhat similar. Mercury had an inflatable airbag between the heat shield and the capsule. Gemini hung at a much steeper angle than Apollo for an edge-first entry.
As for reentry, shuttle again was the most comfortable; the heat resistant tiles allowed it to spend more time in reentry than the ablative heat shields of the small capsules, decelerating at a gentler rate, and the maximum g-force was around 3g.
Soyuz, Apollo, and Gemini all use/used lifting reentry. The center of gravity of the capsule is offset from the geometric center, so the heat shield hits the airstream at a slight angle, producing lift, which keeps the capsule from descending too quickly. Without the lift, the capsule would fall quickly into denser and denser air before it has a chance to bleed off much of its orbital speed, and the peak deceleration is much higher.
When Soyuz' lifting entry works properly, it subjects the crew to about 4.5g maximum. When it doesn't work properly, if for example the reentry module doesn't separate from the service module (as has happened a couple of times), the capsule doesn't produce significant lift, and it goes into an 8g ballistic reentry -- very uncomfortable but not likely to cause permanent injury.
Apollo capsules peaked at about 6g on reentry.
Mercury was brutal: there was no lift, and it came down like a cannonball until the air stopped it; the peak exceeded 11g on the suborbital flights but was closer to 8g on the orbital flights, which descended less steeply. On the bright side, at 11g deceleration the reentry is over very quickly!
I assume Shenzhou is very similar to Soyuz in descent characteristics, but I've never seen any statistics for it.