Based on a 4 second clip of
Music on a 3 year old episode of
Bones, I got turned
On to Plantlife-- never heard of him
Before that, but does great Prince-esque funk!

Skimming through my digital library, a few artists/composers/recording acts that I became aware of from some television show or another:

Alien Ant Farm
Adam Lambert
Ben Harper
Clifton Chenier
Hoagy Carmichael
John Tesh
Kevin Eubanks
Lalo Schifrin
Leonard Cohen
Louis Prima

Lumidee
Mike Post
Mumford & Sons
Naturally 7
Ray LaMontagne
Regina Spektor
Rodrigo y Gabriela
Robert Randolph
Snoop Doggy Dogg
The Black Keys
The Blind Boys of Alabama
The Chipmunks
The New Seekers
The Partridge Family
The Pointer Sisters
Tom Jones
Vince Guaraldi

Walter Murphy
Wayne Brady
Zac Brown Band

I'm sure there are countless others from American Idol, MTV, VH1, & BET alone.