From time to time I help prep someone for an interview: which could be for a job, college entrance, or volunteer position. And always get stuck on the "what's your greatest weakness" question. Unfortunately it's important to plan for that one as it likely will be asked.
Most common given are: "I'm a perfectionist", "I'm a workaholic";
Ones I like: "I'm sometimes too hard on myself when I make mistakes", "Sometimes I care too much", "I wish I had more patience for those who don't work as hard as they could";
Joke answers are risky (in my opinion) - for example, "chocolate", "physics", "kryptonite"; as is trying not to answer - "I'd rather focus on positives";
Today on a flight I found 3 more good responses in the "Cubicle Coach" section of Marie Claire (Aug '08) magazine: "I over research", "I can take on too many projects", "I'm too eager to help my colleagues".
Any good answers not noted?