Well, I'd recommend my case, a Lian Li PC-60 from
Aria for £78 + delivery (I can't remember exactly how much delivery was - about £8 i think.)
Its a full aluminium case, with two intake fans, one out fan on the back and one out fan on a top blowhole. The fans it comes with are pretty decent, and not too loud. To make them quieter the case comes with a built in rheostat for the front two fans, which is a very nice idea indeed.
Its internal design is superb (things like the fact that you can remove the drive boxes you aren't using to get better airflow, and the popin fanscrews they use - everything else is thumbscrews), it looks great, and it keeps your rig nice and cool.
Definitely worth a look - see why people rave about lian li.