Hi guys.
I would like to buy one of those products.
Could somebody mention me advantages & disadvantages of each or just opinions about them.
Thanks. 
I recomend Acid PRO or FruityLoops instead
Cool Edit Pro is great for audio composition, and it has a video track, and enables you to record vocals seprately so you can impose it on a beat. Great for creatin CD audio tracks. LOTS of features, its like the blender of audio, still havent used all the features.
try pro tools - you can find a free version online to test it out!
Well, cakewalk is pretty sucky unless you’re heavily into MIDI… Cool Edit Pro is an excellent audio editor with multi-track capabilities, and it’s a very good choice. I can’t see how these two proggies can coexist on your list since they are two quite different pieces of software. You’d probably want both rather than either one of them.
If you want to make some noise, I’d say give Buzz a go http://www.buzzmachines.com If you know what you’re doing, it’s capable of anything! An it’s freeware as well. Then top it off with a copy of Cool Edit.
Protools
maybe Cubase , Logic Audio, and Reason
ProToolsFree is a freeware version of the ProTools software that isn’t dependent on their proprietary hardware. It’s the best you’ll get for what it is, but it is a serious memory hog, mainly because it tries to do with a normal PC or MAC what it would usually be doing with dedicated hardware. apart from that it kicks ass, i highly recommend it.
BEAT
I like skale at http://www.skale.org as mentioned in the previous post but if you are going to buy… go with cakewalk or reactor from the propellorhead site. I am putting some links up in a bit.
Cakewalk is my choice since it works well with digital audio and has great MIDI control (especially when used with SoundFonts).
But you must have an Intel chip for your CPU. It has problems on AMD systems. I know, it doesn’t work on my Athlon 1.2 Ghz system. It mentions this problem on their site.