If I had to pick one citrus to use for cocktails for the rest of my life, I would choose pink grapefruit. It's as versatile as lemon, but so much more interesting, refreshing, tart, and delightful. This drink is a combo of two of my favorite cocktails that feature pink grapefruit - the Pink Lady (which is made with gin and Lillet) and the Paloma (made with tequila).
Lillet is a sweet, floral, fortified wine that is often classified as a vermouth (it's James Bond's favored vermouth in his shaken not stirred martini). It's not expensive, and adding a measure to any cocktail really elevates it to the next level of deliciousness. It's also a lovely bottle to display on your home bar.
Pink Lady Paloma
2oz Silver tequila
1oz Lillet Blanc
Fresh squeezed juice from half a red or pink grapefruit
Soda water (La Croix Pamplemousse is ideal)
Simple syrup (optional, only if you like your drinks sweeter)
Mix tequila, Lillet, and juice (and simple syrup if using) in a cocktail shaker with ice and shake until cold. Strain into a highball or tall glass and top with soda water to taste. Garnish with a grapefruit wedge.