Who is responsible for launching commercial satellites (like for TV and GPS) into space?

It's kind of hard to imagine private companies launching their own rockets all the time, especially when it's such a big deal when NASA launches something. You wouldn't think rockets would go into space all the time, unnoticed by the media.
Still, I never hear about companies "hitching" a ride on the Shuttle, either.

For commercial payloads, most are launched by private operators- they have to get a permit for the launch.

Some prominent ones- Sea Launch, a partnership between Boeing and Zenit (Ukrainian rocket builder) launched from ships in the Pacific

Boeing (delta II, III and IV)
Lockheed (Atlas rocket)
Arianespace (Ariane 4 and 5)

Well, I was going to say NASA at the risk of being stupid (and most likely wrong), but now I reconsider my answer. Companies like Cox and Dish probably have sections in their orginiztion responsible for launching and upkeeping their satelites. I wouldn't claim that it was one solo company.

In the United States: NASA

Any company that wants to put something into space has to hitch a ride from NASA

There are too many entities out there to list. And , because of costs, the names change too frequently. Obviously, NASA lauches GPS for the military. But commercial satellites, WHEW! Too many companies.

Google the subject and start writin'.

There are private companies working on it. Mostly, however, its NASA, ESA, Russia, Japan, China and India.