Personally, I've never been a really huge fan of major seasonal sales. This isn't to say that I don't like to save money; in fact, I'm one of the most... um... frugal people that I know.
Some have even called me cheap.
What bugs me about big sales, though, is the "race to the Berlin wall" mentality that I often experience with them. Looking to save a few bucks, I suddenly find myself cheek-and-jowl with rushing, grasping hordes of reeking, grasping humanity. In this situation, my buying standards plummet, and I end up purchasing things that I don't want or need, often for the simple reason that some porcine walking disaster area just happens to want them more, and she ticked me off when she tripped me on the way to the half-priced shirts.
In other words, I don't like the person that I become when I'm at a big sale.