>The best advice I would offer you is to obtain US Citizenship.
Generally agree, however, a note of caution and something very worthy of consideration. Once you are a US citizen, you will be required to complete a US tax return, where-ever you live in the world, stating your worldwide income. This can be a tremendous PAIN. It also means that you are effectively inhibited from investing in UK mutual funds and could find it rather difficult to open a UK bank account.
That said, in your situation, being married to a US citizen likely means you filed taxes as 'married' and fall into this situation anyway.