Rockingham
I did a trackday at Rockingham last season on the National Circuit. I had not visited Rockingham before as I've always been a bit sceptical about going there given its four-wheeled focus and that it was dropped from the BSB calendar several years ago. That said I was pleasantly surprised and I would definitely recommend a trackday on the National Circuit if you have not been there before.
The shorter National Circuit is only 1.7 miles long, but the track has some impressively fast corners and several elevation changes. For me the best part of the circuit is the rapid right/left/right section prior to Turn 4 which is immensely enjoyable given the speed you can carry through it. However the track surface is inconsistent, so be prepared to make some minor adjustments to suspension set up as it is extremely bumpy in places. Of note there are some particularly nasty bumps on the apex of Turn 7.
There is always plenty of space in pit lane but make sure you take an extension cable with you if plan on using tyre warmers as the garages are open plan. Other than that the circuit noise limit is 104 dB for this season.