I've got a suggestion take your boat, all your picture were of water, seems like you were missing it 
Seeing as you did the Elan Valley and Lake Vy...whatever (
), you might like a couple of other smaller roads (assuming you haven't already done them):
1.
From Beulah, take the B4358 to Newbridge-on-Wye; proper little rollercoaster, slimwilly first showed me this one.2.
From Rhayader, take the B4518 to Llanidloes.3. From Llanidloes, carry on along the B4518 past Llyn Clywedog, then turn left for Dylife - brings you out at Machynlleth.
4. If you follow the A490 north from Welshpool, you come to the A495; turn right, then immediately left onto the A490/B4391 to Bala.
5. From Bala, take the A4212 to Trawsfynydd. Alternatively, turn right onto the B4391 after the big U around the lake end, for Ffestiniog.
Those are some of my favourites, more for scenery, but still good twisty rides.
