Like my colleague Derek, I played with the New York Times deficit calculator, and this is what I came up with: allowing the Bush tax cuts to expire, eliminating or modifying major tax subsidies like the employer health insurance deduction, and cutting all manner of subsidies. I could have gone farther, but I deliberately left most military spending alone--not because I think it shouldn't be cut, but because I have absolutely no idea how many ships the US should have, or what the consequences would be of cutting their number. On the other hand, I'm relatively comfortable with my grasp of what would happen if we eliminated farm subsidies.
In fact, I generated too much in savings; we now have large surpluses in 2018 and 2030. Tax cut for everyone! Or, er, more public parks!
There's just one small problem, which is that this is completely politically infeasible--any politician who tried to enact my plan would be carried away by villagers waving pitchforks long before he'd finished reading off the list of tax increases and budget cuts.