I hated it so can't really help you on that one...
I usually use Cheezly Mozzarella style - if you take any sealed, in date pack to Pizza Express they will use that instead of their cheese. I haven't personally come across another one that is so widely available and melty. I find if you don't spread it too thick and leave it to cook long enough it's fine (it tastes pretty rank when raw).
I have tried this one, which tastes great but doesn't melt that well (if at all):
http://www.alternativestores.com/ve...cheese/veganic-vegan-grated-pizza-cheese-500g
I can't remember what Mr Singh's in Birmingham use but their pizza is pretty good, especially the cheese aspect.
For a pasta bake topping I use Cheezly with some nutritional yeast flakes (contain B12) and vegan parmesan type stuff - just don't use too much of the yeast flakes or parmesan or it gets quite powdery!
As a side note, I highly recommend Violife for cheese sandwiches! It tastes great straight out of the pack - I really like the cheddar and hot peppers ones.