I suppose it depends if you are processing it yourself or not. As others have said, the chromogenic black and white films, which can be developed at an ordinary mini-lab in colour chemistry are excellent. XP2 has great exposure latitude, so you can rate it a bit faster or a bit slower and get good usable images, which makes it versatile. XP2 also has the advantage that it can be printed normally using an enlarger. It scans well, too, if you are into that.
I used to travel quite a bit with just a compact rangefinder [I use an interchangeable lens rangefinder these days] or with a good quality autofocus compact, and I'd second other people's recommendations of a good quality 400 ASA film like HP5+ [although as it happens I tend to shoot slower films more myself]. I have a preference for Ilford which seems more consistent than some other brands for quality, and it's easy to get here in the UK.