It's hard to know where to start with that
I would agree with the consensus about the first 5-10 years being the best episodes overall. Back then I used to watch endless repeats of the episodes whereas now I tend to only see the new ones once or twice.
Like many of my DVD's I haven't looked at the old seasons in a long time and they are gathering dust in one of my spare rooms
But yeah the early ones are best for me.