Public speaking, followed very closely by making a phone call.
I used to have problems with everything on this list, but thanks to going out with my friends from high school to movies and restaurants I got used to stuff like eating, drinking and counting money in public, talking to people one on one and talking to the opposite sex (only when I've known the girl for some time, and it helps if she's friendly and open).
I'm surprised that nobody has specifically mentioned going to parties as the most anxiety-producing.
Yeah, me too. I can't stand those. I've never been to a club or a party in my life, and I have no intention of ever doing so. I can't even begin understand how people actually enjoy being there, it's 100% suffering for me.
For me, small, formal groups of people from whom I can't escape tends to provoke a lot of anxious feelings.
Same here. In fact, I have more anxiety being around this kind of small formal groups where I don't know anyone than I would have with public speaking, provided I had rehearsed what I had to say a hundred times and I knew I would have a quite audience.