Laptops can be perfectly fine for gaming, i used them for the last 10 years. What i learned though is that good cooling is paramount. Also if you want to use the laptop on your lap or some uneven surface then you *need* a cooling pad. Otherwise depends on the laptop really. I had a Gateway which benefitted about 10-15 degrees from my Zalman NC2000, but my current Asus G751JY has only marginal benefits from it, around 5 degrees celsius.

I've heard that if train a fly to jump on command, that if you remove all it's legs that it will without a doubt go deaf...

Good shit.

...and before you consider a desktop rig (as others suggested), remember in the UK its probably cheaper to move to the Outer Hebrides and have your laptop cooled by the native weather! ;D