When I interview people, I throw them lots of softball questions. One of them is "why should I hire you?". Some people think this is a scary and difficult question. On the contrary, it means "here is your invitation to tell me why you are right for this job. Feel free to brag as much as you like. I will now listen while you tell me what is good about you. Extra credit if you have some clue about what is valuable to me." Interview questions just don't get any softer. Yet some people blow it. They answer a different question, usually "why is it important to you that you can work here?" but occasionally "why do you want to be employed?". Fascinating information may come out of your mouth, but it isn't what I asked for. This of course means that I learn something else from your answer - something about your attention to detail, your ability to think of my needs instead of your own (and if you join us, to think of client needs), and your grasp of the business picture here.
Another question that terrifies people is "tell me your biggest weakness." I generally don't ask this because you just get "well I am a perfectionist, I must have all my work complete and beautiful" or "I work too hard I am so devoted" or "my brilliance shines so brightly that it scares others" or the like - bragging disguised as modesty. I already have a question which prompts you to brag. But the other thing is that not all weaknesses are things you actually need to improve or fix. For example, I sing poorly. I have arranged my life so that this doesn't matter. I would never raise it in a job interview. (If I was interviewing for Canadian Idol, it would be a big deal though, wouldn't it?)
If you do get this question, you want to provide an answer that is honest, that identifies something relevant to your workplace, and where you can say what you are doing about it, but more importantly what you need from them about it. "I work long hours and can tire myself when I get caught up in an exciting project. I really value firms that track overtime hours and give me an extra day off from time to time to acknowledge those long days and let me recharge my batteries." "I have very high standards and when I was younger every client got a Cadillac even if we bid a Pinto. I have learned the importance of requirements and project plans to keep my work in scope and make sure I solve the problem we are tackling in the time we have allowed, but it's still a weakness that I can be vulnerable to scope creep." "I think very quickly and solve problems faster than most people, but I can forget to make sure my colleagues are with me and that we have consensus. I work best in an atmosphere where at least one person can keep up when my mind takes off, and remind me to explain my thoughts to everyone." These answers genuinely reveal something about yourself that would be a fatal flaw in some companies. The thing is, if they're true (and not something you made up thinking this was the "please brag" question) then you don't want to work in those companies. Revealing this weakness will save you from a miserable job. They also set a requirement on the interviewer. Will you give me time off when I have been working long hours? Will you have the discipline and project management to help me stay in scope? Am I doomed to be the smartest person in the room every time? Let the firm assure you (if they can) that they will be a good fit for you.
Take some time to think about your true weaknesses. Lack of experience, impulsive or overly rigid actions, ignoring procedures or refusing to ever deviate from them, freezing out slower thinking colleagues or never making a decision or offering an opinion without checking with everyone else first, skillset that's a little old fashioned, slow learner, new thing junkie, continuous partial attention, tendency to go dark, hesitant to ask for help, afraid of public speaking, horrible grammmar and spelling, everyone has something. Take your time and construct a reply that honestly states your true weakness, then explains the environment you need to thrive given that you are this kind of person. If you like, include something about how you are strengthening that part of yourself already, if you are. Or if that's just who you are (like my singing) don't pretend you plan to fix it. Resolve not to work for firms that can't support you in your weak areas. Never pretend just to get employed.