Affiliated with the Wang Center, the Commonwealth Shakespeare Company (617/426-0863, www.commshakes.org ) has been performing the Bard outdoors for the past decade. The free summertime performances take place in July and August at the Parkman Bandstand in Boston Common .
For two decades, the Huntington Theatre Company (264 Huntington Ave., 617/266-0800, www.huntingtontheatre.org ) has been regarded as Boston’s  top professional theater company. Under the tutelage of artistic director Nicholas Martin, several of its performances have recently gone on to Broadway. The company’s works tend toward well-crafted dramas with emotional storylines. In addition to its main stage at the Boston University Theatre, it also performs at the BCA’s Calderwood Pavilion.
Across the river in Cambridge , the American Repertory Theatre (617/547-8300, www.amrep.org ) has earned an enthusiastic following for its more avant-garde performances that often feature elaborate post-modern stage design. In addition to two stages at Harvard’s Loeb Drama Center (64 Brattle St., Cambridge), the company recently opened the Zero Arrow Theatre (2 Arrow St., Cambridge, 617/495-2668), which has a flexible stage for even more cutting-edge productions.
The multistage Boston Center for the Arts (539 Tremont St., 617/426-5000, www.bcaonline.org ) is a South End  complex that features several modern resident theater companies. In addition to the 360-seat Calderwood Pavilion, the complex has four smaller stages of varying sizes.
Last but not least, the Charles Playhouse (74 Warrenton St., www.charles-playhouse.com ) is home to two long-running Boston favorites, the bizarrely comic Blue Man Group (800/982-2787, www.blueman.com ) and the interactive whodunnit Shear Madness (617/426-5225, www.shearmadness.com ), a cheesy Boston tradition for more than 25 years and 12,000 performances.