Yup, Gin and Tonic is what I was thinking of. Tonic is slightly sweet, but the gin adds an herbaceousness that definitely does not say “dessert” to me.
Another one is an Old Fashioned. Made properly (ie, not from a mix), it’s only slightly sweet. Recipe:
1 shot of brandy, whiskey, or Rye
1 orange slice
1 maraschino cherry
A pinch or so of sugar
Put the fruit in the bottom of a glass, add a pinch of sugar, and 3-4 drops of bitters (more sugar/bitters depending on how you like it). Muddle. Add the liquor, give it a stir, add the soda, stir gently so you don’t make the soda flat. Yumyumyum
Manhattans are also not particularly sweet. Basic Manhattan is Whiskey or Rye, sweet Vermouth (which is not especially sweet), and bitters. A “perfect” Manhattan adds dry Vermouth as well.
Properly-made Margaritas (once again, “properly” means without a mix - and even then, a lot of places add far too much sugar) are not especially sweet, but they’re sweeter than the above recipes. Tequila/Cointreau/fresh lime juice/sugar if the limes are overly tart.
And, of course, there’s the king of dry cocktails: the Martini.