Head out to Moretonhampstead & then across Dartmoor towards Postbridge making sure to stop in at The Warren House Inn for a very very very very very very welcome pint.
Just go up onto dartmoor. The road that runs from Mortenhampstead to Princetown is pretty epic, and the one back from Two Bridges to Bovey Tracey is pretty good, as it the one from Mortenhampstead back into the Exeter (B3212) is pretty epic, but these are all futher north.
As above; Dartmoor. Should be relatively free from tourists this time of year, so you can 'flex' the blanket speed limit quite safely providing you keep an eye out for errant sheep and ponies. To be honest, even off the moor you'll struggle to go far wrong.