So, I've got a couple of options for TLs. After trying to choose one for a few days, I finally decided to leave it up to the people of AH.com.
Options
A Hungarian in Madagascar: Moric Benyovzky, rather than handing Madagascar over to the French after being crowned king, establishes an independent state and is subsequently bankrolled by both the Americans and the British to interfere with, respectively, British and French aims in the Indian Ocean.
Empire of Steel and Steam: Oda Nobunaga survives Akechi Mitsuhide's assassination attempt and becomes Shogun--Nobunaga subsequently leads Japan to a more open, expansionist, and western-based foreign policy. Less militarism!
Greater Guiana: The Dutch manage to keep the rest of Guiana in 1814. Not exactly fleshed out, but I'm interested in this one.