First off, I don't drink alcohol, so I'd be getting soda instead.
That said, but with virtually the same atmosphere, if it was a member of the staff: Graham, Yahtzee, or Paul. I need a laugh, and these guys really know how to supply them.
If it was a fellow member here: BaraNoHime. She is possibly the most easy-going, open-minded, and fun-loving (not to mention flirtatious) people I've ever meet on the internet, and infinitely more-so than anyone I've met in real life outside my siblings. It'd be nice to be able to sit back and loosen up with a nice, cheerful conversation for once that doesn't involve me hiding my geekier interests. (If you're reading this Bara, I hope that didn't sound creepy. My first impressions of you just make it seem like you're one of the best types of sociable people)