In reply to DaveHK:
Lescun: stunning views and access to easy walks around the Pic d'Anie, Pic d'Ansabère or Table des Trois Rois
Etsaut in the Vallée d'Aspe: easy access to the GR10 including the nice chemin de la mature, possible to push to the west side of the Pic du Midi d'Ossau
Laruns in the vallée d'Ossau: easy access to very nice walks around the Pic du Midi d'Ossau (to climb it requires a little bit more than walking though). Some minor summits like the Pic du Larry, Pic d'Ayous or Pic des Moines have very good views on the Ossau
Cauterets and Luchon are good bases too (or maybe a bit further up Luchon in Gouaux or Cazeaux)