What was the most challenging team you worked with? Why?

There are some people who create challenges at work by simply opening their mouth. Some individuals waste time and energy by causing distractions or being lazy. Working with personalities that are different from you can always pose an extra challenge. If you have experienced issues with conflicting personalities or worked with others who just didn't seem to carry their weight or weren't willing to work hard, share how you made an effort to bring the team together and work collaboratively.