Re:
Blimey, what a question.
I guess you need to be a little more specific maybe?
For me it's got to be a Bontrager as my first thought, although the ones I've ridden are pre-'92 so it depends how you define 'production'...
As noted by CCMdoc, the Rascal is a great ride. Always my bike of choice, and I still really lust for the '93 in 'whatever' fade it was from the MTBPro review of the same year...
Love/loathe/snob they do handle well and I love mine rigid or FS - it makes me [feelingly] a better rider than I am, and is always very predictable. As Elev12K can vouch from Wales a few years ago - I predicted I was gonna go arse over, did, and almost caught the bike mid-air... :]
There's a big UK bias toward Kona, and I still get jitters [in a good way] thinking of '93 Explosifs and Kilaueas - but that's purely based on looks and perceived 'yes' ness and I've never actually ridden a Kona....
I'm gonna stick with Bontrager though. What you see is what you get, I respect the thinking behind them, the thinking isn't masked, and they're beautiful to ride.
The steel S-Works are nice too mind...
Quality of production as judgement for 'best'? Gotta be Miyata. I have seen many, and they are all exquisite - be they NOS / abused / loved / shoved - all structurally tight and perfect, apart from the 'ex-HB' one offered a couple of years ago which was shagged and had a separated top tube / seat tube lug. But, if it was genuine, it didn't have an easy life as a 'production' hard tail - especially a hard tail modded to 'soft tail' duty...
From all this crap I've written, there is one forum member who has owned / ridden / sold more production / other bikes than anyone I know either side of the pond, and his posting is surely needed here.
So, Jez-4-bikes-max where are you?!
P.S. Im STILL looking for a '93 RaceLite - and Dan from Germany can politely leave the next one for me...
Cheers,
BB.