Well that is all up to you!
1. What is your budget?
2. Do you want performance?
3. Do you want user changeable parts?
4. What applications do you use besides just music apps?
5. Do you need more than one hard drive?
6. You need portable laptop? or home Desktop?
7. Do you want to have Pci slots, Video Cards, Modify anything?
better for people who are less "Tweakheads", not computer savy, and may not want to
spend time tweaking or modifying. More user friendly for you if you
want to get to work without any operating system / tech thought.
You just Plug and play and Go! Usually way more expensive than PC.
Also it's alot like foreign cars, only serviceable at mac outlets, and such.
I know a friend who was charged $500 for just a power supply that went bad inside
his Mac G5 or iMac. And he previously worked at Mac as Genius.
For audio production, you usually want two or more HDD,
so if you want alot of room or performance, you should go with mac tower, can be very expensive.
Mac tower Prices
One thing to watch out for is, when updating Osx, check out online, google
"DAW problems with Osx Updates".
I know alot of people always have Mac on the fritz after updates,
they have audio or driver problems, so make sure you keep up with
updates possible problems. Macs also are very pleasing to the eye, looking all
space age silver, they are pretty and Look professional.
Unless you have a mac tower, you can pretty much rule out having
video cards, pci Audio Interfaces, and so-on, so keep that in mind.
Make sure you check to see if you have USB and FireWire Ports,
for periphials like Audio Interfaces, Midi Controllers, and that sort.
Windows can work very well if you keep it configured right.
(I will have later tutorial about this).
From a Clean install, proper HDD configuration and the less periphials you can have on a DAW workstation, you can achieve amazing results.
Windows Vista / Windows 7 are microsofts biggest blunders.
They took away some of the most loved features about XP / Pro
I have found XP 64 bit Professional the most streamlined / Tweak easy.
(I have started testing and tweaking Win7 as well, will post later).
On one hand Microsoft is forcing you slowly to upgrade and only work with Win7.
By not allowing certain new softwares to work with anything before vista.
On the other hand, most DAW's will still work XP 64 pro.
Good thing about windows, you can make any creation on your own build.
Have numerous HDD's. Add nice GPU's, and have Pci Audio Interfaces if you want.
There are great tweaks which make Win an amazing operating system to
use for a DAW. I currently have my Win Desktop running only 5 services, while I make music on my DAW. Talk about great CPU Performance.
My personal recommendation is to use ASUS brand computers and parts.
Logitech products, AMD not Intel. I would recommend getting a motherboard
with out onboard Video or audio, you know the money you spent on the bord went to the parts on it and not on the audio/video components. Dual GPU support is a plus.
Always disable onboard audio/video, and use your brand of Audio Interface for you DAW for sound. Also disable onboard Video, use pci GPU.
It takes work load off cpu, freeing cpu for DAW / VST / Audio.
When looking for Audio Interface keep an eye on reviews first, do your home work.
I have found Mbox 2 Pro / Mbox 2 / Digi 003 Rack / Tascam Us-224 or similar are very good interfaces.
At least a Dual core, or more.
64 bit a plus.
2Gb Ram or higher is better.
HDD speeds at 7200 or higher. (SATA)
1 HDD for operating system / Software (and Page File).
1HDD for VST Plugins + Sample Collections (if you have large collection).
1HDD for Audio Play / Recording
(optional - 1HDD Recording -separate 1HDD Playback)