I like the cut of your jib. WW1 wasn't the good vs evil battle WWII became; it was just the largest of many European wars. Would be interesting if the German Empire survived it.
I'd knock of Kaiser Wilhelm II. Hopefully he'd be replaced by someone who agreed with Bismarck's more pragmatic and effective foreign policy, which in turn might spare Europe from the horrors of World War 1.
Here's a controversial suggestion: Gandhi. I know all the hippies love to swoon over him because of the whole non-violence thing, but his retarded socialist economic ideas held back India for decades after his death and are responsible for untold amounts of suffering and misery. I know it's probably overly simplistic to blame him for India's economic screw-ups, but I can only imagine what they would have achieved if they'd adopted a more free market system upon independence.
Edit: After a bit more reading I guess that Jawaharlal Nehru probably deserves a much greater share of the blame for the post-independence economic mess in India. I'd assassinate him instead.