I'm almost finished "Days of Fire: Bush and Cheney in the White House" by Peter Baker, which has been fantastic so far. I'm pretty selective with the novels I read but I love political books...most of the time. The trick is sifting through the partisan bullshit (which is incredibly difficult at times) and not just pick up some wildly conservative or liberal piece that doesn't even try to understand the events it's discussing. I hate that.
Baker doesn't do that at all. He's fair to Bush, and while more critical of Cheney, I think that's balanced and deserved. He's incredibly detailed and goes through every notable event of the Bush presidency, with particular emphasis on Iraq. Seriously, if you're looking for a fair and comprehensive account of Bush and Iraq, this is for you. He covers everything in great detail, from the initial discussions to invade through all the important on-the-ground moments and turning points (up to the end of Bush's time in the White House of course). You really get a tremendous sense of Bush the man, how lonely he was, a president who genuinely believed he was doing the right thing, and you see the toll it took on him when it became apparent that his vision was failing. Really good book.