Used to go to loads of races about 10 years ago, sadly the cost means I only get to one or two a year now. Thruxton is a good circuit to watch, especially at the first chicane. It’s just not the best for seeing a lot of the circuit although I haven’t been there for a few years! I always try and get to Brands Hatch once a year though (do they still go twice a year there?) as it’s my favourite circuit for viewing anything, despite it being a 3 hour drive each way for me! The dive through Paddock, up Pilgrims and into Druid’s always produces good close action for most formulae. BTCC, DTM, classic F1’s, all good there. The trucks are just mental! Plenty of places to shelter if it’s windy, the inside of Druid’s is handy.
There’s usually a decent amount of stuff going on between races at the MSV circuits (Thruxton isn’t one) to keep people entertained if one of the party isn’t a big motorsport fan. Can be grim in the wet though, you see the die-hard fans then.
Might try and get to Rockingham this year as I’ve heard it’s good viewing.