I have had laptop since 1990. I had commodore, dell, HP, compaq, Apple and Sony. I had problems with all but sony.
Couple of my friends have Alienware. The performance is awesum but the only problem is that in case you face any issues and you take it to their service center without warranty, they are going to rip you off.
Go for Hp they have great combination with affordable price. I own 2 laptops one Apple and another Hp, Apple works quiet good than HP.
I think for your choice dell is the best for better screen and can be used as a rough use of laptop but not the sony.