Another thing worth trying is armagnac. It's similar to cognac, except it's distilled in column stills instead of pot stills and it's a lot lower profile and usually a lot cheaper for the same quality. To me, Delord 25 year Armagnac was a revelation. In terms of actual cognac, I like Maison Surrenne Petite Champagne Cognac. I use it, or Delord Napolean (depending on whats available) for mixing. I prefer the cognac for mixing and the armagnac for sipping, but your mileage may vary.