I know everyone slates Rosecliston (just outside of newquay) but if you are going early season (mid - late June for us) when its not so busy we've always liked it. No hassle from the staff, dont get stuck 2 yards from other people and we have never had trouble with noise. After midnight its always seemed fine to us. Will definitely go back anyway.
They are happy to take groups with noise deposits (we always got ours back) so unfortunately you do get a few 16 year olds kickin about but like i say we always enjoyed it!
Price gone up a bit in the last year or 2 though but worth a look for younger groups.