I never much used to care for the classic gin & tonic, but I've gradually come around and now heartily embrace this easy and well-known highball. It's an absolutely essential summer drink, though when I make mine I can hardly resist a little tweaking.
I'm sure legions of mixologists have used both the name and basic concept of this one before, both being far too obvious. But I don't care.
1 1/2 oz London Dry gin (Beefeater here, any would do)
1/3 oz maraschino liqueur (I shouldn't really have to specify Luxardo anymore)
3-4 oz chilled tonic water, to taste (I use Q Tonic generally, but have been dying to try making my own)
1-2 dashes orange bitters, to taste
Build in a Collins glass over large ice cubes.
The G&T has become the GMT (Gin, Maraschino, Tonic). The orange bitters here lend a little complexity and keep the drink from becoming too sweet. I find that Fee Brother's new Gin-Barrel Aged Orange Bitters are perfect here, though the regular version works well too; you want something with a nice fresh flavor. The maraschino is meant to be an accent, since this is still a highball at heart.