I always enjoy finding at least one new place to eat out when I'm traveling to some place new. It makes the trip that much more interesting if the rest of my meals are at fast food joints or restaurants I've been to before (chains or local).
On my trip to Argentina next week, I'm doing a little of both - planning a few nice meals (Sunday brunch, NY Eve dinner). I'm doing a lot of meails though on the spur of the moment.