This drink was a discovery a few months ago, and it's been a regular ever since.
It's called Essoil's Calamansi Iced Tea. Off hand, the name is a bit weird since it sounds like something you'd put in an oil burner. But weird name notwithstanding, this drink is really, really good. It has the right blend of sweetness, the flavor of calamansi and lemongrass, and the kick of tea. If I could drink this everyday, I would.
The thing is, it's only available in 7-11, and not all branches have it. That's why whenever I come across one, I drop everything and buy it.
This goes up there with Vita Lemon Tea as my favorite bottled tea drink.