The first example is code duplication, and almost every line is suspecious.

    var listOfGoodFoos = new List<Foo>(); // is listOfGoodFoos a good name?
    for(var i = 0; i< listOfAllFoos.Count; i++) // is the loop condition correct?
    {
        if(listOfAllFoos[i].IsGood) -- the only interesting line is burried in here
             listOfGoodFoos.Add(listOfAllFoos[i]); -- is i the right index variable? (vs. j, k, n, especially in nested loops)
    }
    return listOfGoodFoos;

The second example is obviously correct, and highlights the condition.

A quote from Tony Hoare comes to mind:

There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies.