Tap water in a 1qt container that has been with me at almost all times for the past 2 months.
Coke in a can.
Beer in a bottle, and it has to be good beer, not cheap shitty watered down piss, err, I mean, pilsner style beer. There's only a few good beers in cans, and all of them have a propellant in the can (Guinness, for example).