I agree and this often comes up - I think most people's understanding of the geographic South West is Devon, Cornwall, Dorset and Somerset.

That said, in my Rugby playing days even Buckinghamshire was included in the South West Division of the English Rugby Union!

 
I'm always cynical about these surveys. A few years ago, one nominated Tidworth on the Hampshire-Wiltshire border. though I would concede that it's not a bad place for a soldier to be posted to, and I was quite impressed when I walked around the town last year. (Re-opening the railway to Andover for the public might give it a boost.)

My "Southern Region" Government office in Reading embraced Bucks,Berks,Oxon, Hants, IoW - and Dorset, which was anomalous, especially as other Government departments with which we liaised included it in the South West. This  dated back to the Second World War, and when my office closed in 1982 Dorset was handed over to Bristol, with my passing over the files in Marlborough High Street.

Talking of Marlborough, the town has great appeal with its range of shops and great countryside. Of the places mentioned above, I can understand the inclusion of most, with my deepest reservations being about Pangbourne, though I acknowledge the benefit of its good rail service to Reading and London.

I liked Chippenham when I visited it last year, leaving my car on the outskirts and walking in. (Not only too mean to pay at a car park, but apprehensive about any technology that might challenge me in trying to do so.)

 
Your own likes and preferences might not be perfectly reflected by this site, which says it is "now the UK’s No1 luxury lifestyle site for ABC1 women".

 

My choice of English counties - the site quoted was England only,  and I chose counties that have services provided by GWR.  Should probably have added Worcestershire. Buckinghamshire is an interesting case as it wraps around from west-of-London to north-of-London.

 
I am intrigued by the definition of South West etc, including Oxfordshire and Berkshire doesn't leave much for South East.

Government Office for the South East used to include Oxfordshire, Berkshire, Buckinghamshire and Hampshire (+ IoW) and the other south eastern counties. Then muddied by South Central of Buckinghamshire, Oxfordshire, Berkshire and Hampshire (+ IoW). Think South Central has gone out of fashion, except by the Met Office, although I get the impression that Oxfordshire sometimes drifts into the Midlands. Do not ask about Milton Keynes, who I think prefer to be in a world of their own.

 

I agree, Malmesbury is a great town - my sister used to live there.  Property prices there are, however, rather pricey. 

There used to be a railway station - that closed to passengers in 1951 and to goods traffic in 1962, with the tracks later removed. The site where the station once stood is now an industrial estate and car park. Typical of several Cotswold towns - see also Cirencester and Tetbury, for example.

 
Hang on - that's not right, Melksham's not even in the Wiltshire top 10 

Personally I wouldn't want to live in Bradford-on-Avon, although that's probably because I'm seeing it from a visitor's perspective - parking is difficult and it's a pain to drive through. Visited Malmesbury (Wilts #2) recently and we did like that; pity there's no station.

I liked Chippenham (Wilts #7) when I lived near the town centre for a couple of years not that long ago. Having a pedestrianized high street makes it so much nicer to wander around than Melksham, and only having to take one train to work was also a big plus. But the (very) large number of houses being built around it would put me off moving back there.

 

That is the Forest of Dean for you.

 
From a Muddy Stilletos survey - the best places to live:

Penzance, Cornwall
Bradford-on-Avon, Wiltshire
Bampton, Devon
Sherborne, Dorset
Frome, Somerset
Henley-on-Thames, Oxfordshire
Cowes, Hampshire and the Isle of Wight
Internal Server Error, Gloucestershire
Pangborne, Berkshire