We have been the first week of December once, the second week of December twice (and we'll be there the second week again this year). We were there for the parade taping, and I remember thinking Main St. was a madhouse (no surprise), but the rest of the park was fine. No more crowded than the second week for us. The second week has always been great for us crowd-wise, especially on weekdays. If it's a nice weekend day, you might get more local annual pass holders.
Edited to say.....the Pop Warner football is the first week of December, and that might make things a bit more crowded that week! I forgot about that when answering the first time. This is one of the reasons we've chosen the second week....so we can avoid the football craziness. It's still less crowded than other times of the year though, I'm sure.
Laurie in OH, mom to
Alex, 11 years old
Julianne and Leah, 10 years old
Audrey, 2 years old
WDW visits in 1973, 1986, 1987, 1999, 2000, 2001, 2002, 2004, 2005!
Currently planning a December 9-16, 2006 trip!