Have reached 6 months and it feels fantastic. Wouldn't say I was a non-smoker rather than an ex smoker yet.
My quit is good and can't see me breaking it, however, I think complaicency will be my downfall, the moment I think this is a doddle is probably the day I make a stupid decision. Never ever want to go through the first few days again or the first month and although the quit has become easier and easier there isn't one day I'd like to do again.
So to all you starting off or recently given up smoking keep going, each day is easier than the last and each time you think that having a smoke would be nice/ok/not a problem, remember how hard it has been to get to where you are already and think about having to do it again. Never take another puff.