My "specialty" drink is vodka and soda. Its easy to make, its vodka and a splash of soda water. Sometimes I'll throw in a splash of cranberry too.
I was a bartender for years and as a result, I don't like sweet drinks. I've seen far too many drunk people who didn't realize how drunk they were getting because the alcohol was masked by the sweet ingrediants in the drink. I can make just about any drink there is though, and we always have the main liquors on hand when we have a party. What I used to do as a bartender was put all my drink recipes in a rolodex and anytime someone asked me for something I didn't remember how to make all I had to do was flip to it in my rolodex.