dont buy a laptop unless you really need it, when they break you know about it, very expensive to repair as can custom builds,
like w.h said it all depends what you need it for,
you can get some good package deals if you shop around, stay well away from pc world, im sure there still beieng investagited for conning people.
buying a package deal can work out better for warranty reasons, with custom builds you hardly get one so if anything goes wrong out comes the cheuqe book, currys/dixons arn't really that bad,