If you do, consider going for a desktop and not the joke that is a ''gaming laptop.'' You'll save a buttload of money, and can potentially upgrade it (generally for $100-$200) a couple years down the line to extend its life. While hardware has out-paced software over the past few years, laptops still gouge dearly for a video card that actually has capability, and you're at their mercy because it's a rare laptop where you can actually change out parts on it. You could get a svcktastic $300 prebuilt desktop and slap a $50 power supply and $150 video card in it, and you'd have a reasonable computer for modern games.
Queue
I've already started looking for a desktop, it's going to be considerably cheaper seeing as I don't need a monitor or any other accessories. I've found a Dell XPS tower which I would get if I had the money right now, it will cost about £550 (about $800, to my estimate). Here's the specs:
Windows 7 Home Premium
Intel i5 2.8GHz Processor
AMD Radeon HD 6670
6GB RAM
1.5TB Hard Drive
Although, looking on the options today, they've added a few more graphics cards, namely the NVIDIA GeForce GTX 560, AMD Radeon HD 6870 and the AMD Radeon HD 6950. Problem being, they both add £100+ to the price, and in the 6950's case, £300, which I certainly won't be able to afford. I've seen a demo of the HD 6670, and I think it'll be good enough for my purposes, it's been shown to run Portal 2 with no hitches whatsoever. And, as you say, I can upgrade at any time, so I'll probably get it with the 6670.
Then again, this whole purchase will be happening in the near future, so there might be a better deal nearer the time! xD
Thanks for the advice guys, I want to return to PC gaming after a long hiatus, and I need all the advice I can get!
GrimHippy666