There are many things you can say. This type of question doesn't have a wrong answer. All answers will be correct. So the best answer is how good you can make the answer. A mediocre answer will be something like completing a project on time. You can say this, but add another twist to make the answer a little better. Here is an example.
This answer is showing that you believe in delivering great quality work. Moreover, it is implying how much you value team work. If you value teamwork highly, then it is safe to assume that you would make a great team player.
Learn English speaking much FASTER by downloading the TalkEnglish Offline Package and submerge yourself with over 8,000 audio files and over 800 pages of lessons! Then you can study without Internet connection and also listen to audio files using your MP3 player at any time. Go to the English Download page and download today!