I know this is an old topic, but one thing no one pointed out is that the ordinal (first, second) refers to the occurrence of the event, not the anniversary. In other words, the reference to "annual" means that it occurs every year. "2nd Annual" means the second occurrence of the event, which occurs annually. Grammatically, "second" and "annual" both modify the noun "event." Some people are mistakenly assuming that "second" modifies the adjective "annual," which is not correct.

There is a difference between the first event and the first anniversary of the event, which presumably would be when the second event would occur, and thereby be established as "annual" by virtue of an actual year passing between events. If you are having a First Annual Fundraising Banquet, you are just having a fundraising banquet. When you have the second banquet a year later, as planned, it becomes the 2nd annual banquet. The first event is the first occurrence, but it isn't annual until the second one occurs. The "annual" designation includes the first event, even though it isn't annual until the second. Therefore, the 50th Annual event is actually 49 years after the first event (1+49=50, imagine that!). The first event marks the BEGINNING of the first year, which doesn't become a year (or annual) until the year ends. The first Anniversary marks the END of the first year, which is when the second year begins and the second annual event occurs. Progressing, the 50th Anniversary marks the 51st annual event - the beginning of the 51st year. It's like our calendar, we don't start at zero, we start at one. If we start at one, then ten years later, it's the 11th annual event, which occurs on the 10th Anniversary. Not sure why people find it so confusing. It's really quite simple if you do the math!

And while it's true that technically anything happening once could be referred to as the first, the use of ordinals implies a series. In common usage, you do not use a numbered list (such as an outline) unless the "list" has more than one item. (a list, by definition, includes more than one item). In this context of sequence, there shouldn't be a first without a second. Obviously this doesn't apply to things like superlative records (the first person to achieve a milestone), but that is a different form of numerical usage. With scheduled events, "first" implies a "second," which might not ever happen. Inaugural is a good choice of words. "Premiere" means "first," so you wouldn't use that unless you would use First anyway.

The best way to avoid the conundrum, one way or the other, is to use the year: "The 2012 Fundraising Banquet." If you do it again the following year, you can call it "The 2013 Fundraising Banquet" or "The Second Annual Fundraising Banquet," take your pick! Or you could be like the NFL and use Roman Numerals, but that gets tiresome after you get past X.

BTW - Frank Rizzo's hypothesis that an anniversary is a year plus a day is incorrect. When you are counting the passing of days, you don't count the first day, because it isn't complete until the second day begins. It is one year from anniversary to anniversary. Assuming a normal calendar year, it is one day from January 1 to January 2. It is two days until the 3rd, etc. The anniversary marks the beginning of the 366th day, but 366 days haven't passed until the day is over (in other words midnight January 2), at which time, the Anniversary has passed, too!

Sorry for being so verbose - there was so much to respond to!