Depends what you want your laptop for and how long you expect to go before replacing it, for example you might buy a lower spec Dell and have the peace of mind it will probably have a longer life span than say.. most Acers. But an Acer gets more bang for your buck.
A friend of mine recently recommended Novatech where you can build your own rig and they have a pretty solid price range.
Also you might want to make sure you get a new laptop with the free windows 7 upgrade (I say free it normally costs £15 handling cost which saves you about £30 if you were to upgrade).
