Located on the campus of Truman College, Pegasus Players has been a company in residence there for many seasons. The company produces a variety of different works at the campus O'Rourke Center for the Performing Arts, many of them focusing on multicultural themes and issues. They also generally do at least one musical a season, which until recently has always been a Sondheim show.
The space is very large for a non-union company, and the company has steadily built its reputation as a go-to place for high quality theater. The neighborhood itself can be a little sketchy (it's right in the heart of Uptown), but the theater is very nice.