My wife bought a 2004 Focus 1.6 when it was 2 years old and our son now uses it.
She replaced it with a new Mk2 1.6.
That was traded in in October for a new Mk3 1.6.
IMO, the Mk1 was the best drive but I still dislike the Fisher-Price dashboard, even if it is made of nicer materials.
The Mk2 had nothing that I could recommend over the Mk1 and we never for a moment considered holding on to it any longer than necessary.
The Mk3 is a completely different car and is my favourite of the three. It has better materials and build than the Mk2, drives better and is hugely quieter. It feels like a bigger more expensive car and I'd put build quality close to that in my C-Class. The only criticism is the electric power steering which I think feels a bit vague.