Frankly you could make a top 50 of these and 35+ of them would be from South Wales. Barry and Llanelli are particularly dim sounding especially the women, Merthyr is practically Neanderthal with the men (their accents too). Pontypridd doesn't sound too think but from personal experience I know never to trust anyone with that accent to even do basic maths without a crate of bananas and pack of crayons to help them.