Ten years ago, I would have said Jadot, who was then the only one of the big negociant houses who made both great reds and great whites on a consistent basis. Today, to me the clear answer is Bouchard, again because this is, in my opinion, the only “big 5” producer today making both great reds and great whites on a yearly basis.
My take:
Bouchard–Incredibly good Chambertin Clos de Beze and Bonnes Mares and these two wines are consistently one of the top two or three wines produced from those appellations every year starting with 1999. The Corton and estate Clos Vougeot are also very high standard wines, and the Malconsorts is the rising star of the red portfolio. The reds seem to get better here with every vintage.
On the white side, the Montrachet, Chevalier Cabottle, “regular” Chevalier Montrachet and Corton Charlemagne are also consistently at the top every year and the Meursault Perrieres isn’t far behind and seems to be closing the gap. Bouchard seems to be doing well from a premox perspective, and they are both extremely open about the issue and proactive to the point of spending significant money to further minimize the problem, including their new high tech ultra-low oxygen bottling line and now weighing each cork individually to exclude low density/lower weight corks.
Jadot–Two consistently great reds produced here: Musigny and Beze. The Bonnes Mares and Gevrey Clos St. Jacques are very good, and exceptional in exceptional vintages, but they most often are not the stars of their respective appellations. The remaining reds, while above-average, and in some cases having good QPR (e.g. Beaune Ursulles) generally don’t excite me.
I used to love the Jadot whites, particularly the Chevalier Montrachet Demoisselles, the Montrachet and the Corton Charlie. But the wines took a significant turn for the worse starting with the 2000 vintage. Jadot had very little premox from 1993 to 1999, yet it seems to be out of control from 2000 on. I’ve quit buying Jadot whites completely, and as mentioned by Jim Coley above, Jadot/Kobrand basically ignores premox and the response seems to be “what premox problem?”
Drouhin–I have to say, after three decades of trying, I’ve never liked the whites here. I have the opportunity to drink seven and a half year old Montrachet De Laguiche every year, and while it is usually good to very good, it is never thrilling and never seems to me to be worth the asking price. On the reds, I’m a fan. The Musigny, Bonnes Mares, and Grands Echezaux are usually stars from their respective appellations and Griotte, Amoureuses, and Clos Vougeot are just a notch behind the top wines from their appellations. One caveat for me is that Drouhin had clearly subpar years in 2006 and 2007 and simultaneously raised their pricing considerably adding insult to self-inflicted injury.
As to Louis Latour (once my favorite producer of Corton Charlemagne) and Chanson, the wines are below average and not worth mentioning in the context of Bouchard, Drouhin and Jadot.