I have never been to Snetterton as its a colossal 4 hours away from me. Where would you guys recommend spectating from ?
Best place to be is generally the new banking on the start finish straight. From the top of there you've got good views of the start, Riches, Palmer, Hamilton and Oggies with enough of a view to see what is going on at Montreal, Williams, the first half of the Revett/Bentley straight and even Coram if you get the right spot. You'll be lucky to get a spot on the top of the banking for BTCC weekend though so you may end up further down which will mean no view of the start, Riches or Coram. Even then it's still the best place to be to follow a race.
The big banking in the middle of the circuit will give you a good view of Agostini with a 'long range' view of most of the rest of the circuit.
The Esses (Or Brundle/Nelson if you insist on using the new names) is a good spot when the 200 circuit is running but I find you're waiting too long for the cars to come around on the 300, plus it's main benefit is being able to watch whilst sat in the car which probably won't be an option for BTCC.
If you want somewhere quieter then it's worth the long walk down to the far end of the banking that runs along the Bentley straight to the Montreal Hairpin, you'll have a decent view of the hairpin plus Williams as well as reasonable views of Hamilton, Oggies and Agostini. Due to it's relative remoteness this area is generally deserted although it'll be busier than normal for BTCC simply because it's near to the camping.
Russell always used to be busy as it was where all the action was, the new corner, Murrays, isn't anywhere near as good from a spectators point of view but it still draws crowds primarily for historical reasons and secondly because it gives photographers a good close up shot.
If you're there for the weekend then it's worth a wander out to the Bombhole at some point during practice/qualifying (They've recently put a small grandstand up here too but based on the prices for GT/F4 weekend I wouldn't expect it to be getting much use). Not a lot of racing going on here but it's an impressive corner to watch them have a go at.
There are also supposed to be big screens up for BTCC which may influence your choice of viewing.