Don't know, I like group work. Some projects are just to big for one head and besides that it is great to share the same feeling of having accomplished something with the group after.
We once played a managment game in university, where 10 companies each consisting of 4 players started with the exactly same situation and had to beat the other 9. There were 6 periods that were equivalent to one year of real time. The game went on for 6 weeks. You could decide whether you research a new product or how much you wanted to produce. Whether you invest in your comapny image or if you want to buy new machines, and a lot more.
My company won in the end
. We had invested in R&D and luck was on our side.
That was a real group achievement and it was pretty fun.