Oulton Park - my local so BTCC, MGCC, MSVR races etc, somehow British GT falls on the wrong weekends
Silverstone - BTCC, WEC, GT1, MGCC
Donington Park - BTCC
Anglesey - the old version to watch friends at track day, the new version for stage rallies
Mallory Park - I remember watching the MG Metro Cup and some Jaguar sports cars (possibly replicas)
Rockingham - BTCC
Brands Hatch - I won some BTCC tickets
Nürburgring Nordschleife - turned up on way back from Switzerland nervous about doing a lap in my car that the exhaust had detached on and full of suff but it was a VLN test day so had a great time watching that and wandering the paddock instead.
Been to the hill climbs at Shelsley Walsh, Prescott, and Goodwood for shows and Loton Park for the hill climb.
also driven a couple of mini track days at Curborough Sprint track in a Rover Metro and Honda Prelude
Best for a relaxing day is Oulton Park, it is genuinely a nice place to spend a day. Best day out Anglesey for the drive up, and backdrop by the sea or some of the other Welsh Rally stages where you can make it a day wandering in the forest.