I think that putting it as 'soooo sad' is a complete understatement IMO. To this date, it has become the ONLY episode where I have been so saddened to the point of shedding tears (Not even the episode where Butterfree left got close to that) I'm normally very immune to sadness, (Depression is another thing though) and I rarely ever (Stress on 'ever') cry when I get saddened by something.
To rate it would be pointless. The rating would be way off the scales... This episode is the deepest (emotionally) episode (yes, deeper than the Butterfree and Pikachu episodes) to date, and it tells about how Ash, Misty, and Brock actually feel about each other through the entirety of thier journey together.
If you'll excuse me, I have a mind to clear now...