I feel sure someone would have mentioned this, but re-reading the thread it seems that Bude hasn't come up, which by my reckoning has its four nearest stations on different lines:
Okehampton (24.9m), Gunnislake (25.8m), Chapelton (26.2m) and Liskeard (26.5m), all distances as the crow flies.
(I'm not as hot on rail geography as most people here, but I assume that we consider the Okehampton and Barnstaple branches to be separate lines?)
With the distances this tight, it might depend on where in Bude you measure from. With the next-closest stop along the Okehampton line (Crediton) being some 15 miles away, you have all stations from Yeoford to Barnstaple, as well as all stations on the Gunnislake, Looe and Newquay branches, and all mainline stations from Ivybridge to St Austell closer than Crediton!