A large number of people spend most of their time at work. Our life is divided into three equal parts: 8 hours - sleep, 8 hours - work, 8 hours - family time. So, in the most cases, one's co-worker plays an important role in one's life. From my opinion, the essential characteristics of a co-worker are the following.
First of all, a person who works closely with me must like his job. I think it is very important for a person to feel satisfaction with his job. My husband is a software developer. He is fond of his job and people enjoy working with him because they see how many energy he puts into his job.
Second of all, my co-worker must be persistent and never give up. I like when people who came across a problem try to solve it, find a good decision instead of looking for another person to hand it over. Another important aspect of this is that a good worker should always ask himself "What can be improved?" and suggests new solutions.
In addition, he must be a good team player. In the modern world good communication skills and the ability to work in a team are among the common position requirements. Personally, I think it is great to help each other, share new ideas, develop new solutions, etc. It helps to create a team spirit and improve a labor productivity.
Finally, my co-worker must be punctual. He or she should finish the job on time I think that It is unacceptable to make the rest of a team wait while a person finishes his or her job. Also, my "ideal co-worker" should always be ready to offer his or her help and be supportive.
To summarize, I think if a co-worker possesses all of these qualities mentioned above he can make work with him really enjoyable and productive.