Rum: I dig rum in the summer, especially very dark rum with ginger beer. My brother makes fun of me because he says I only like rum that takes like Scotch. Bilgemunky as a long list of rum reviews that are much better than what I list below.
Goslings Black Seal is probably my favorite rum. It is dark, not very expensive, and is great both strait and in cold ginger ale or ginger beer.
St. James extra old is an awesome rum. I think most of the St. James rums are good, but complex. This one is best straight; it is smooth, dark, and flavorful. This is a rum that my brother said tastes like a dark whiskey. I wouldn't mix this rum; it has a complex flavor, like fine whiskey.
Mount Gay extra old is my buddy TC's favorite rum. It is a medium gold color and is heaven as a mixer. It is ok straight too, but usually we drink this in coke or OJ in the summer.
Appleton estates V/X is the only Appleton estates rum I have tried, but it is great. I use it both straight or as a mixer. It is a dark amber, and is great in the summer.
Vodka: I am not vodka expert, so this list is short. However, I would say that I have found some good vodkas when traveling in eastern Europe. Slate has a review of vodkas, which is fine. I don't think any of the vodkas they list are as good as the Lithuanian vodkas I have had.
Lithuanian vodka (yes that is the brand name) is my favorite vodka. As far as I can tell, it is not available anyplace BUT in Lithuania. It is a rye vodka, and it is amazing. It is the best of the Lithuanian vodkas I tried.
Sobieski is another really good Lithuanian vodka. It comes in cranberry flavor, which is my Lithuanian friend Joana's favorite vodka. Don't mistake this for the crappy western "flavored" vodkas, this is not sugar water, it is not even sweet. I haven't seen this vodka outside of Lithuania.
Tequila: this will have to wait until I get back to the US; the tequila in Europe isn't tequila as much as it is grain alcohol with a slight tequila flavoring.
Regional: a mix of various regional drinks I have stumbled across that are not available many places.
Vana Tallinn (so smooth, ha ha, Carl is a tulip) is an Estonian liqueur that is pretty interesting (and good, depending on your tastes). It tastes a lot like very dark rum (e.g., Gosling's black rum), and apparently goes good with Russian champaign.
Believe it or not, Japanese whiskey is pretty good, which is not surprizing if you know that the father of Japanese whiskey, Masataka Taketsuru, studied the art of distilling in Scotland,. If you are ever in Japan, try some (e.g., Suntory).