Crimea is the best success, but its because it really more of an annexation of a population that is ethnically same as the annexing nation.
I don't want to give what Russia did legitimacy, but its closer to self-determination than most liberal internationalist (the IR theory, I don't mean US liberals) will give it credit for. Crimea was only part of Ukraine due to the dictates of the Soviet Union and had only been part of it since 1954. Then again, maybe I'm overestimating how strong Taiwanese nationalism is.
In places like Syria, you see what happens when different ethnicities fight over territory. It's a bloody mess and everyone is worse for it.
Israel is in a different position since they really just want the land and not really the economy and people on the land. They are ethnically cleansing and then populating the area with settlers.
I was going to say that is unique in this age, but its really not all that different from what China did in Tibet or is doing in Xinjiang.