In reply to mc2006:
NE arete and Las Espadas traverse on the Posets is classic at that grade, especially if you start along the Bardamina - Paul arete (which is fantastic). Makes a great circuit from the SE. Nearby is the Gourgs Blancs traverse, and just across the valley are the Maladeta, Aneto and Pico Alba, all prominent 3000m peaks with F/PD routes, and mostly on superb granite. The northern loop on the Vallibierna is good too, great positions although less sustained and on dodgier rock. There's also some spectacular aretes and rock spikes not far away near the Perdiguero, haven't done them but they look great. Benasque is a great base for all these (bars, gear shops, camping just out of town).