For me that would be factory silenced variable weighted Realforce. It's not perfect and while I still have it, it's not my daily driver because of couple reasons. Case coating fades quickly, it's nearly impossible to get blank coloured keycaps and topre has problems with consistency in feel and sound.
Probably worth mentioning that my second favourite is my metallic blue Filco with MX Blues from 2012. It feels (and sounds) great with stock keycaps and with thin blank PBTs I got on ebay shortly after I got the keyboard itself. It's now beaten up as hell, was used by myself at work, my wife in her office, and our friend for gaming for couple months. Also our cat used it as her bed for a while
Switches are worn a little and not as consistent as they were but it's still one of my favourite boards of all times.
My daily driver is currently few months old Filco with GMK black double shots for which I'm getting aluminium case (already ordered, but it takes a while to get here from China).
The switches do feel a bit different than the old board but I think it's mostly matter of breaking them in properly.