This is by far one of the most common and interesting of the classic cocktails. The balance of sweet (Italian Vermouth) to bitter (Campari) to herbaceous (gin) makes this the perfect Trojan horse to sneak new ingredients to less experienced drinkers. The ratio (1:1:1), and the fact that fresh ingredients are not needed makes this an easy drink to throw together for a party. It also lends itself to creativity: e.g., use whiskey or tequila instead of gin, vegetal Gran Classico instead of Campari, a delicate dry vermouth instead of sweet.