My husband and I would like to travel from Barcelona to San Sebastian in Oct.
Which would be the easiest and most comfortable--bus or train?
For a trip of that length the train would be more comfortable, and very easy. There are 2 direct trains a day, taking just over 5 1/2 hours. If you book 2 months ahead you can get a significant discount on the tickets. Renfe is misbehaving right now and doesn't show prices, but one of the authorized agents (Petrabax) shows a discount fare of $39, while the regulare fare is $98. Those are slightly higher than you would pay buying on Renfe.