CD or Phonograph for my Martin Speakers USA 206B ?

This is my first pair of speakers and cost $300 new and are a bookshelf 6 inch woofer with a dome tweeter and are small but have a lot of sounds on CD's that I never heard on my friends speakers playing the same CD. I have bought some good records and people have said a turntable sounds good but I do not see any in stores, Are there that many brands and why aren't they in stores? Thanks Albert

Ok, Thanks for your help, unless I run across a good table I will stick with the CD's and my Sansui does have a phono hookup with ground, You are right I do not like the MP3.