I know this thread lost steam more than a year ago, but recently my mind has been set on a scenario that I feel ties quite nicely into this one -- namely, a scenario in which the Cold War is avoided and communism is largely confined to the borders of the USSR. The more I think about, the more I'm convinced that the Cold War and its effects (namely the US' embracing of interventionism and the rise in anti-American sentiment both domestic and abroad) are largely responsible for the heavy hits the US has taken to its reputation over the decades. If you can somehow find a way to come to an agreement with the Soviets that Finlandizes Eastern Europe and Germany and allows for free elections there, while also reaching a workable settlement regarding Korea, then I think the seeds are planted for a notably less tense global situation, one in which the US doesn't feel the need to re-arm after its post-war demobilization and is instead content to retreat into (relative) isolationism.
I'm inclined to believe that much of the goodwill the US had attained through its efforts in WW2 and subsequent relief campaigns in Europe were to some extent squandered by the general Cold War ugliness they later partook in. Absent the Cold War, I think a more inward-looking US is more successful in portraying itself in a positive light and an example to be followed by the rest of the world. There's also the matter of a lessened/no second Red Scare making social democratic policies and the like more palatable. I think it's very likely in such a scenario we'd eventually see universal healthcare passed in the US (thus removing one of the more common criticisms many foreigners and Americans themselves have of the country). The US will still have many of the domestic issues it had OTL of course, especially with regard to racial discrimination, but I think the world at large would be less inclined to lob criticisms at a US that likely never took up the "leader of the free world" mantle.
And so, if you can just find a way to prevent the Cold War and have the US opt instead to go down a path of more "inward perfection" as opposed to interventionism, then I think anti-Americanism will end up a far less prevalent phenomenon than it did OTL. In any case, even in the most optimistic of scenarios the US is bound to have quite a few detractors, both due to the aforementioned domestic issues and the fact that any country the size and scale of the US is going to step on somebody's toes. For example, a friendly policy toward Israel as in OTL is going to see them gain the ire of the Arab world.
Would love to hear anyone's thoughts on the matter.