My dad gets it for free off his Chinese students when they come back from their holidays lmao.
I tend to prefer Japanese cold green tea. In the UK I tend to get Sencha cold green tea tea-bags from Mount Fuji and tend to get through about 1ltr a day.
When in Japan I tend to drink Itoen bottled cold green tea, (usually at least a couple of bottles a day).
I do find it annoying that the bottled tea in the local oriental supermarkets always seems to be sweetened or have lemon added both of which I find disgusting ...