Just one of GWSR's stations sees a 7 days per week bus service: that's Cheltenham Racecourse Station as it's passed by Stagecoach's Bishops Cleeve bus from Cheltenham Spa station, which even has a 20 minute interval service on winter Sundays.
But... the racecourse station isn't actually served by that bus, the nearest bus stops being half a mile up the road or half a mile down.
That reminded me of two others.
a) Bus service 10 from Dorchester to Weymouth. Once it leaves Dorchester's 'burbs, it doesn't stop until it gets over the top of the hill and into the 'burbs of Upwey. Which is a huge shame as there's an excellent and well loved path along the top of the downs which it choses not to serve. Not only a long horizontal distance, but a big vertical one too!
b) Melksham Station, nestling in the junction os two A roads along which buses travel (I was going to say "speed" - but, no, they stop at the multiple traffic lights) on their way to Atworth, Box, Corsham, Bowerhill, Melksham Forest, Semington, Beanacre, Sells Green and Devizes, none of which has a railway station.