Does anyone have some suggestions for a good multi-variable/vector calculus book? I have a fairly reasonable math background - managed to self-teach myself calculus through Micahael Spivak's text Calculus pretty successfully - and I'm looking for something that's fairly rigorous. One of my math teachers recommended either Tom Apostol's text Calculus: Vol 2 or Spivak's text Calculus on Manifolds but I'm not sure if these texts are going to be beyond me (mathematically speaking). Price isn't really an issue but a cheaper text would be nicer. So, does anyone have some suggestions?