Distilled spirits, once in the bottle, really don't age. There's one type (either scotch or bourbon) that I thought I saw a note on Thirsty Traveler that it did still age in the glass, but I've never been able to confirm it. If it's an unopened bottle, it's still good (but not necessarily better or worse than when it was bottled).
Liquors have sugars and sometimes flavorings mixed in, and these WILL age and oxidze over time, especially once opened.
Beer and wine will both age in the bottle (or can). This is again due more to the other stuff (sugars, hops, tannins, etc.) than the alcohol. Some styles will age better and more gracefully than others (some just flat out go stale). Beer will not skunk from age, it skunks due to exposure to light (particularly UV light). It's a reaction between the light and the isomerized alpha acids in the hops that causes this. Darker bottles (i.e. brown) help guard against this. Miller Brewing uses a hop extract in their beer, which is why MGD can be sold in a clear bottle without skunking (unlike Corona).
Any type of alcohol is best stored in a cool, stable environment. Hot temps can be bad, but large and frequent changes in the temperature are even worse. Darker places will help with issues relating to light.
Yes, I do spend FAR too much tim learning about this stuff....