Who are the main greasers in The Outsiders by S.E. Hinton?

In Chapter One of S.E. Hinton's novel The Outsiders, the first person narrator Ponyboy Curtis describes his "greaser" brothers and friends. The term greaser refers to the young men who live in the poorer part of the city, which is the setting of the novel (Hinton has admitted that the novel is based on her youth in the city of Tulsa, Oklahoma). They are called greasers because they tend to wear their hair long and slicked back with plenty of hair gel. Ponyboy first introduces the reader to his brothers, Darry, the oldest, and Sodapop, the middle son. The three brothers recently lost their parents, and Darry acts as guardian to his brothers.
Darry is described as tall and muscular. He was once a very good athlete and excellent student in high school, but now works hard to keep his brothers together. He often clashes with the often dreamy and sometimes irresponsible Ponyboy. Sodapop is described as "movie star handsome" and Ponyboy idolizes him. Throughout the novel, Ponyboy compares his brothers, with Darry often being referred to unfavorably and Sodapop portrayed as more understanding. In the end, Ponyboy comes to the realization that Darry truly loves him and is just doing what he believes is best for his brother.  
Two important greasers in the novel are the wild and unpredictable Dally and the shy but lovable Johnny. Most of the plot revolves around Johnny's killing of a Soc and the later episode where Ponyboy, Johnny, and Dally become heroes by saving several children from a burning church. Tragically, both Dally and Johnny will wind up dead by the end of the novel. The other two greasers often mentioned are Two-bit Mathews and Steve Randle, who are close friends of the Curtis brothers and loyal companions.