Personally when it comes to desktops i always build them myself, saves a lot of money and with the huge selection of cases available to buy...you would have to be pretty fussy not to find one you love.

If building one is not a possibility for you though, and you want a high performing PC i would personally go with a Dell XPS. As mentioned earlier...Dell owns alienware, but you pay for the branding with alienware. You can get a near similar spec XPS and save a fair chunk of cash, and being an owner of a XPS Laptop i can certainly vouch for the service and performance of the range.

As for your argument on the car, you buy a Porsche to drive round and turn the ladies heads...you don't buy a cool looking PC to do that, you do it to get the Geeks to go "oooh ahh". That's my point of view but at the end of the day its your cash and it's your opinion. If you get an Alienware you will certainly not be disappointed.