First, I know this question has been asked several times before and that in the end, it is mostly a matter of personal preference, but reading all the threads about the subj
Using this.age could help distinguish between the backing store of your Age property and an age parameter for a method on your object:
public bool CheckIfOlderThan(int age)
{
// in here, just using "age" isn't clear - is it the method parameter?
// The internal field?? Using this.age make that clear!
return (this.age >= age);
}
Of course, in this case, you could also give your parameter a less confusing name to avoid any clashes....
But in the actual definition of the property - reading and storing its value in the backing store - adding the this. doesn't really add anything. Some people I know just prefer to use the this. prefix all the time - not just when it's needed - personal preference, really...