The best things to tax have a couple of attributes:
1) Goods that have little or no elasticity
2) Activities that have high negative externalities (and, implicitly, moderate or high elasticity)
3) Easily legible to the State, meaning things that the State can easily monitor and send people at to extract resources from.
Labor is very useful to the economy; you want to encourage it, not discourage it. Same with capital and technology. And they're both relatively tricky to track down.
Land taxes satisfy 1) and 3), so I'm all for them, though they've fallen out of favor.
But what seems best of all is carbon taxes, up the whazoo. As high as you can set them.
There are two countervailing tendencies: carbon is a deadly pollutant, and fuels that emit carbon as a side effect of use are essential to the functioning of society. A carbon tax lets you straddle that: at low levels you're taxing a negative externality to discourage it, which is pretty much creating free value (in the same way that government reducing crime creates value). But, to the extent that fossil fuels are absolutely necessary to the functioning of society, their use is inelastic: at higher levels, an increasing proportion of the tax would be passed directly on to consumers, so the tax is minimally distortionary once you hit that inelastic area.
Best of all, domestic production is very easy to hunt down and tax: a couple dozen very large corporations handle the vast majority of fossil fuel extraction, so you simply track them down and have them all write you a very large check once a week. The only real trickiness is handling rebates for domestic exports and tariffs on foreign imports--the implementation of which would make or break the scheme--but that's surmountable.
Set a sky high carbon tax. Make it revenue neutral by setting the tax's revenues equal to the costs of abolishing capital gains and corporate taxation, which are not as economically efficient as a carbon tax and double as a sweetener to Republicans and the Chamber of Commerce. The USA and world end up a whole lot richer.