--------------DOWNLOAD REAPER------------

Pro Tools is the industry standard - mainly because of when it entered the market and because it runs off a stable Mac platform. It is excellent for interfacing with heavy duty hardware and is pretty user friendly. The problem is that it is not good for midi and you cannot run VST instruments. It is also insanely expensive plus pc's are evolving at a very fast rate and are a lot more cost efficient - at this stage you can easily get a pc spec'd up to the same level as a Mac.

Cubase SX3 or Cubase 4 are my softwares of choice simply because I started out on the Steinberg and am very familiar with the packages. I also prefer pc and the Windows OS. If I was starting again though I would get Reaper. It is free to download and there are no crippled functions - you are asked to pay the vendors once you have tried it. The reality is that for $50 you get all of the same functionality of Cubase and ProTools including VST plug-ins and midi (it costs around €250 for a commercial grade license for use at a pro recording studio). Reaper is as powerful as the pc it is installed on unlike ProTools which has limited number of tracks (you can have 1000 tracks in Reaper once you hardware can handle the cpu load).

The Reaper forums are very active and there are daily updates. It was created by the guy who made Winamp, he is currently positioning it very cleverly to nudge in and become as widely used as Steinberg (Cubase/Nuendo) and Pro Tools. There are already some pro studios using Reaper.
Forget all of the other free downloads, this one is the only way to go.
Get it here: http://reaper.fm/download.php