What are the best Room Accustic Treaments members have found?

I  am looking into adding some room acoustic treatments to my room.  I am just looking for advice on some simple room treatments that fellow members found worthy of purchase. 
@ geofkite  I asked why you scoff. Can't answer, no rational reason? Seems you're not short of inane comments with nearly 19K posts.

Name dropping skills,  hmmm, reminds me to drop your name into my folder titled 'Pathetic"
"The suggestion of crowded bookshelves, curtains, carpets and clutter is no more than guesswork. Adding any or all of these will have an audible effect, unfortunately it probably isn't an improvement. The books will just collect dust and the drapes and carpet are only narrow- band absorbers."

Wrong, but as elsewhere, you`ll need some skills and patience. You need to know what you are doing. Listen to this guy, he`s a bit skilled: 
you'll need some skills and patience.
A few decades of experience helps as well... and not backing down to the 

If I were designing a recording studio, obviously a whole different approach is required. However, the last thing I want in my media room is recording studio acoustics.