s55,
There are many things to be considered before buying a laptop. Directly buying laptop or any other electronics item without any research work will land you into troublesome future. First and foremost thing is warranty cover. Basically, there are two types of warranty in laptop: International and Local. International warranty is cheaper in cost but then you have to pay for the repairment and shipping charges for it. Plus it takes much time of the product repairment. On the other hand, local warranty is expensive but you don't have to pay for the repair charges under the warranty period and the product is repaired by the Company Authorised Dealers. Distributors such as POP and Unique technologies have repute of serving good products.
Second thing is your requirement and budget constraints. Now again here taste varies from people to people. Core i7 handle graphics and computing power appreciably. Moreover, if you are into gaming, you can buy a lappie with decent discrete graphics card that will satisfy much of your modern gaming needs because laptops purely are not for gaming purpose. You can research about the price tag using google.
Third thing is that be sure to buy laptop with vents built sideways as fan below the laptop will cause your system to heat much due to almost no air flow between that thin space. Sometimes, buying from foreign markets has vulnerability that the laptops are designed according to THEIR environment, not according to Pakistan where we witnessed extreme temperatures both in summer and winter. Dell, HP and Sony are popular among Pakistani consumers.
I bought in january this year a Dell Inspiron N5520 Core i7-3632QM with 1 TB HDD, 1 GB ATI Radeon graphic card, 8 GB RAM and i am very much pleased and satisfied with the decision i made. Solidly built and no any issues of heat. Very great and responsive CPU power as I once had to design poster for my thesis using Adobe Photoshop and it was fun using it. I regularly play modern games such as NFS Hot Pursuit 2010, NFS MW 2013, Call of Duty MW3 and games run pretty awesome.
In the nutshell, I would recommend the following whatever laptop you buying dear:
(1). If buying from Pakistan, always buy from company Authorised Dealers. You can see the dealers list through company sites. Though there are many websites offering laptops, I will prefer from authorised dealers as it will give a peace of mind. And to tell you that foreign markets are also not full of saints. They might be cheaper but in the end you will be the one who has to pay. So make your decision wisely.
(2). Go for 3rd generation Core i7. Awesome response and great CPU power.
(3). Dell laptops have unique service tag number below the product. Visiting the dell site and entering the number will give you complete warranty information about your laptop, when was it shipped, and latest windows drivers that are periodically updated. I don't know much about HP and Sony. May be some other users with HP and sony can help.
Best of luck with your purchase.