if in Exmoor may i suggest;
B3290 from Bampton up over the hill to Fai cross covert, Right here on the B3188 to Elworthy and right again onto the B3224 back over the moor to Lynmouth (hairpins here)
Also B3227 from Bampton to south moulton, umberleigh, Great torrington and on to Stibbs cross. then the A368 to Holsworthy, left here onto the A3072 to Hatherleigh where i run out of good roads and it becomes a bit like north devon triangle so easy is it to get lost.
If in cotswolds, Chipping norton to Cirencester via burford is a winner.A361 and B4425 i think