I know, I know, this topic gets covered here and there, but I thought it might be good to have a thread for it.
I'm specifically thinking about liquors and liqueurs (the ones that don't turn rancid, i.e. Campari, Chartreuse, Cointreau etc). For instance, from what I've learned, in about 2007 Campari stopped using natural carmine dye in their product, and the taste is said to have suffered.
Chartreuse has been covered in other threads.. I think the older bottles have a more intense color to them.
I found some Chivas Lochan Ora (scotch liqueur) bottles that must be 30 years old. 70 proof, it seems to be popular for some.. I tried a mini once and it was seriously sweet. I see Wild Turkey Liqueur (the old hexagonal bottles), 80 proof (70?), and pick them up, but haven't opened one yet.
I do see dusty bottles of rum, gin, etc. sometimes. Pusser's, which was highly praised in the "Rum forum" thread, and a bunch of gins that I've never heard of. I'm always game for stuff like Cointreau, especially if it is cheap.
There's often a lot of choices. I'm often on the fence about lower-proof items like Galliano (30 proof). I figure some of them, if cheap, are a good way to stock a bar for cocktails.
What dusty bottles do you look for?