Pitch Perfect is about an all-female a cappella group rebuilding its reputation after one of its members threw up on stage during a competition. It's a fairly realistic representation of the collegiate a cappella social structure and features the International Championship of Collegiate A Cappella, which happens annually.
Glee is a show about a high school glee club that began airing on Fox in 2009. Sometimes they perform a cappella, sometimes they perform with instruments, but they are representative of the shift from chorus music to pop music.
The Sing Off
The Sing Off is a singing competition that debuted in 2009. It features 16 professional a cappella groups competing for a recording contract and $200,000. The show will start its fourth season later in 2013. Pentatonix, the group pictured above, won season three and is now famous beyond the a cappella world.