A great drive for me is to start at Worcester, A44 all the way to Rhayader, left onto the A470 down to Builth Wells, right onto the A483 to Llandovery, Lower Rd to Llangadog, left onto the A4069 through the Brecon Beacons National Park and then back home via a different route.
Most of the roads on the trip are VERY enjoyable to drive but the A4069 through the Park is quite simply THE BEST DRIVING ROAD I’VE EVER BEEN ON, it’s amazing! Good road surface, 2 lanes (not too tight), sharp corners, sweeping corners, undulation and visibility is really good so you can take the racing line a lot.
I’ve added a map below for anyone interested in doing the drive.

A few pics, best bit isn't visible here. Might take some more when I go again!

