Depending where you're coming up from but Moel Fferna if coming up the A5 or Hendre Spar if via the A55. Those are both regulars so you may well have been there.
Around Blaenau... Rhosydd East is a good trip. Conglog is worth an hour so. Diffwys and Cwt y Bugail well worth visiting, and it looks a good weekend for walking the Rhiwbach tramway on the way to various places.
Metal... Two already mentioned, Bwlch y Plwm nice little top to bottom through trip. Pant y Wrach more of an explore with a couple of pitches. Drws y Coed near Nantlle. Plenty of options 😉
my orders are to sit here and watch the world go by