Very interesting reading (open the PDF) that only looks at the tax side of the equation (nothing about spending, which is rarely cut anyway - cue the great sucking sound).
Tax Policy Center estimates of each candidates' tax plans.
For general tax/spending projections:
Congressional Budget Office
And just for giggles, one of my favorite Flash creations ever:
Death and Taxes
And for a state by state electoral map look (forget national polling, it is irrelevant):