I've also read that Vitoria is supposed to be a lovely city and would like to visit it. I just returned from a trip to Spain where I spent 2 nights in San Sebastian. I would highly recommend Hondarribia. It's only a 45 minute local bus from SS and is a lovely, small typical basque town. I fell in love with this place. The bus drops you off around the corner from the tourist office. Inside they have a very good map of the old town on top of the hill (very short walk). You walk up and come upon a beautifully preserved old town - I felt like I was in a time warp. I rambled around for a couple of hours just in awe. At the bottom of the hill just past the tourist office is a lovely street with wide sidwalks on both sides and shade trees. I'm sure it's a favorite for the evening paseo. This street is lined with little cafes and shops. I found a wonderful restaurant just off this street and had a great lunch for less than 10euros (menu del dia). The village is right on the sea and you can also take a short ferry over to visit other local villages in France (I'm not sure which cities as I didn't have my passport with me and will have to return for this).
Just want to warn you that it was pretty quiet so if you're looking for alot of night time activity it might just make a great day trip for you. However, I could have stayed a couple of days here just wandering, eating, sitting at cafes and soaking it all in.
Let us know how your trip goes.