A proper one with good air flow, look at the HAF 912 or Storm Enforcer.
like ilysaml said, good airflow is always a must, but you dont have to break the bank to achieve that.
The CM Storm Enforcer looks like a really nice case. Got great cable managment, air flow and other nice features. If your looking for a case with even better airflow, I suggest you look at something like the Corsair Carbide 500r.
ok thx for the answers, but about the mob i heard that the asrock isn't a good choice for OC....