I don't want to be "that guy" but I will be that guy.
DON'T BUY ALIENWARE.
So, here is my question to you, and what I would highly recommend -- Do you have any friends who can, or any interest yourself, in building computer?
Why? It's cheaper, You become a smarter individual. You are officially part of the PC Master Race.
Why not Alienware?
Well, they are overly expensive for one. Two, they svck at building computers. How do I know this? Well, I was like you many years ago. I was a bright-eyed pre-teen looking to get my first computer to play Half-Life! I heard Alienware is the coolest, so I knew immediately that they were the ones I wanted, until the unit arrived.
Let me make a long story short:
- They forgot to plug in the power connector the motherboard, so the thing didn't power on out of the box.
- It came with Windows ME (who made ANYTHING with Windows ME back then???).
Now, if you don't have any other alternatives or you are just feeling lazy (nothing wrong with being lazy!), then Alienware might be your best bet. But, if you can fit the round peg in the round hole, and not try to fit the square peg in the triangular hole, then you are qualified to build your own computer (it literally is that easy).