I would use them in the following order:
1) the Ternary operator
2) example 3, but indented properly
3) either 2 or 4, they are basically the same. I would go with whatever the general styl was where I worked.
I agree with what jake said about omitting the unnecessary curly braces. I have never caused or seen a bug caused by new code being added and someone thinking they were part of an if statement but they weren't because of the lack of curly braces. If someone ever did do that, I would ridicule them mercilessly.
You'd have to torture me to get me to use number 1.