Well I'm English so he hasn't effected me.
However, I do like the fact he has tried to push universal healthcare for America, it's something that's been a long time coming. People can't exactly accuse him of asking where the change is any more because slowly it's happening. I think he will also make things more efficient domestically once the recession is in the past, which isn't hard to do after Bush.
His major tarnish is the promises he hasn't kept about the war on terror. He said he wanted to withdraw soldiers out of Iraq and Afghanistan, but that hasn't happened. He also said he wanted to close Guantanamo bay, he announced it on his first day; But he has back peddled since then.