This was the most romantic Friends episode of all times. In my eyes it was sooo sweet how Chandler carefully prepared everything and almost messed it up. He made Monica believe he was never gonna marry her chasing her directly into Richard's arms. It was also nice to see him again and see that he finally realized he wants all the same things that Monica wants - but he's so definitely too late. I'm so happy that it all worked out that well in the end.
The proposal couldn't have been any better. Having Monica start and then Chandler do the rest - it was such a perfect thing for their relationship. I could have cried. It was so romantic and I'm so happy that's finally done :-)