I would like it to have a decent graphics card, 4GB and perhaps a 400GB hard drive.
What laptop is a good make but gives you best money value. eg: someone told me Toshiba was a very good solid make but they primarily did business machines so their 'gaming' laptops were pricey. Whereas Acer gives you more money value for the spec but they are more fragile...
Not sure you will get much of a gaming laptop even for £750 but here is a review of the top 10 in the USA, many of which can be found over here. It will give you an indication of what you can get for your money.
click here is another site that is very useful for comparing performance. Other pages on this site give lots of information, including games performance of mobile graphics cards. click here may give you some indication of medium-long term reliability. It's not gospel, though.