Marcos a zar 480, 02965-454163 (http://www.elgualichohost...). very popular and comfortable backpackers hostel. offers very nice rooms and excellent travel information. more like a hotel than a hostel. not very cosy/familial.
Posada Del Catalejo
Mitre 446, 02965-475224 (http://www.posadadelcatal...). excellent family run hostel. friendly english speaking staff.
Gobernador maiz 545, 02965-456457 (http://www.hostelviajeros.com). good location and very friendly staff.
Hostel El Retorno
Comfortable friendly hostel with a some private rooms and many beds in dorms. They offer pick-up at the bus station. You can call ahead to reserve.