In a nutshell, all the literary/TV tries either 1) fail miserably due to the bumblings of the time traveler, 2) end up working, only leading to an even worse outcome, or 3) actually CAUSE Hitler and WWII as we know it.
Now, I wasn’t aware that this was such a common trope. I’ve seen the Doctor Who episode, Let’s Kill Hitler, which actually had little to do with the big bad himself, and was more about developing one of my favorite Who characters, River Song (for a good intro to all things Who, watch the two-parter Silence in the Library). Hitler was quickly forgotten in the first ten minutes or so.
And I remember watching one of the items on io9’s list – the Twilight Zone episode (in full here) where Katherine Heigl (!) time travels to visit baby Hitler. She’s not there for a friendly visit, and not to give it away, but history incorporates her mission with no noticeable change in the timeline.
Several of the other books/stories/etc on the list are intriguing, and worth a look. Read this clever short story here, in its entirety.
The moral of this story?
Time travel as a dramatic device is great for one reason – there are endless permutations and possibilities. One simple concept – killing Hitler – can be spun in countless entertaining ways. As long as it’s well executed, it will work.