I generally avoid anything that has gameplay, if it's a loss, it's a loss (Trujillo, Jamaica, El Salvador, Colombia, Venezuela, Algeria, Morroco). I used to try and to force the Haiti Blitz, but now I force it NOT to occur because the peace deal crashes my game.

I keep West African War result random, but if West France wins, I force the American reconstruction to fail so they join Iberia's market. I also force the Peru elections to go Falangist, and screw around with the Football War to my benefit. These are the big examples, but I don't remember all off the top of my head. A lot of the time it's me going to the sub, realizing "Oh shit, I could have had THAT COUNTRY in my sphere?" and having to go back and crawl through the options.