Studio One Free
'Nuff said. <img src="smileys/smiley36.gif" border="0" align="middle" />
Free, maybe, but you can't use VST plugins. If you want totally free, go for LMMS! Or bite the bullet and check out FL Studio. The cheapest edition is $49 but really worth it. I've been making professional music on computers for more than 15 years and I own practically every major music making software, and FL Studio is the best value for the price.