I don't really drink either option, but of the two I guess I'd go with tea. Have only had coffee once or twice and thought it was gross. The fancy stuff they serve at places like Starbucks I'm sure I'd like better but I can't bring myself to try them as they look pretty unhealthy on top of being expensive.
Tea I don't care for either, but have had a modest amount of Green Tea. Some restaurants I went to in Japan and here in the States had it complementary and a lot of sellers I've imported games from have included mix packets as a thank you gifts. Green Tea Ice Cream is pretty good though; had my ice cream cone stolen by the native deer when I visited Todaiji in Nara.
Hot drinks in general I don't care for. Not even hot chocolate.