[AbyssUnderground]

I was going to say check out eBuyer as they have loads of back-to-school deals on at the moment.

Avoid HP and Dell as they tend to feel very plastic and badly built from my experience. If you want cheap and cheerful, go with Acer. Some would disagree but I think they're built well, but the only downside is the components the use are cheap, so sometimes they go wrong quicker than other brands. Never put me off though and mine have been great.