While I've never been converted to the idea of a gaming laptop (one word: upgrades) for those who are MSI has something for you...
The GT740 and GT640 are 17in and 15.4in variants designed to get Crysis blazing around your screen and making your mates' desktops look rather silly until they upgrade and you can't. Consequently inside you'll find Intel's high end Core i7 720QM processor on a PM55 chipset, a near-prerequisite 4GB of RAM and nVidia's GeForce GTS 250M tour-de-force with 1GB DDR3 VRAM.
Naturally enough both models also ship with Blu-ray, 2MP webcams, 4-in-1 card readers, Gigabit Ethernet, Bluetooth 2.0 with EDR and wireless N while a 640GB HDD also hits the spot. Windows 7 and HDMI make their obligatory appearances. Apart from the screen sizes, where they differ is the GT740 packs in four speakers and a sub compared to the 2.0 arrangement on the GT640.
As you might expect, neither is particularly portable at 395 x 278 x 33-39.5mm and 3.2Kg (GT740) and 395 x 278 x 33-39.5 mm and 2.7Kg (GT640) tough that's reasonably compact for this category. The six cell batteries aren't likely to last long, but that's not really the point.
Interestingly, MSI is shipping both models at extremely similar price points with the GT740 retailing now for £1,399 and the GT640 just £50 less at £1,349. Personally speaking, if you're going down this route then you might as well cough up the minimal extra to get the even more uber-beast with the better sound.