I would say my biggest flaw is trying to do everything myself and trying to control everything. You know that thing of "If you want something done right, do it yourself?". Yeah, that's me right there. Team work is a problem for me most of the time. Mostly because the 'team' usually doesn't work together, or they don't work as fast or efficiently as I would like them to. I hate being dependant on other people, especially regarding work. It's annoying. Because of this, I either over-work myself, or I get pissy and strict with my colleagues. I don't like it, but I do it. Urgh. I should learn to delegate more. And trust people better.
What about you??