Glock G21: no experience, but have shot the G20 [for frame size] and G30SF.
Glock G30SF was ok.
XD, no experience shooting, but didn't care for what felt like a high bore axis. Made me concerned about muzzle 'flip', due to height in hand. Probably unfounded, but it didn't 'float my boat'.
M&P .45: like it A LOT. It feels pretty soft in my hands.
As was previously stated, the Ruger P97 feels VERY soft, has a DA pull around 9lbs and a SA pull of around 3.5 lbs on my version, with factory hammer spring installed. It probably is the softest, even if the recoil impulse feels, well, odd, due to the recoil rod's design and how it reduces recoil.
1911s feel pretty soft also, as long as they are 5" full size, with full-strength recoil springs [nothing watered down].