I like community theater - especially around Christmas time. Not sure why, but I enjoy the holiday programs much more than the other shows.
Here's a list of Milwaukee area theaters to check through out the year
Acacia Theatre Company
http://www.acaciatheatre.com/
Alverno College
alvernopresents.alverno.edu
The Bay Players
http://www.thebayplayers.com/
Bel Canto Chourus (sing along Messiah)
www.belcanto.org
Carroll University
www.carrollu.edu/campus/services/artscalendar.pdf
Cedarburg Cultural Center
cedarburgculturalcenter.org
First State Children's Theater
http://www.firststage.org/
In Tandem Theatre
intandemtheatre.org
Marcus Center
marcuscenter.org
Marquette University
diederich.marquette.edu/COC/Mainstage-Season.aspx
Memories Ballroom (dinner theater)
memoriesballroom.com/theatre.htm
Milwaukee Ballet
www.milwaukeeballet.org/performances
Milwaukee Chamber Theatre
http://www.chamber-theatre.com/
Milwaukee Choristers
http://www.milwaukeechoristers.org/
Milwaukee Repertory Theater
http://www.milwaukeerep.com/
Milwaukee Symphony Orchestra
http://www.mso.org/
Milwaukee Theatre
http://www.milwaukeetheatre.org/
Next Act Theatre
http://www.nextact.org/
Pabst Theater
http://www.pabsttheater.org/
Wilson Center for Performing Arts
wilson-center.com
Skylight
http://www.skylightopera.com/
Soulstice
soulsticetheatre.org
South Milwaukee Performing Arts Center
http://www.southmilwaukeepac.org/
Sunset Playhouse
sunsetplayhouse.com
Waukesha Coral Union
choralunion.org
Waukesha Civic Theatre
waukeshacivictheatre.org