Gosh, too many to list.Aromatics? What blends are you referring to? Over what period of time?
Flakes and ready-rubs by Kolhasse & Kopp come to mind. Sometimes the topping evaporates and you're left with a less-complex tobacco.
Another example for me was HU Director's Cut. The first several smokes were excellent after opening the tin. But I noticed that after some time the tobacco became "plainer" and less complex. It's not bad, in any case, but those first few smokes were outstanding.