I feel like the consensus is that Memories of Murder is the better movie but having seen both now I think they're dead even. Memories of Murder is probably better paced and more consistently engaging but Mother is a fucking gut punch
Finally got around to watching this today and holy fuck I loved it. I still have goosebumps from the ending.
Someone pointed out to me today that the family being held hostage by someone with their finger on a button is an obvious reference to NK and I have no idea how I never noticed that before.