We finally find out what exactly happend the famous night Chandler and Monica got together in London.
It all starts when Chandler and Monica can't find a minister for their wedding. Phoebe's says that you can get ordained on the internet and perform marriages. Joey offers to do it and after some hesitation they agree to it.
Joey has some trouble with his speech (personally I thought it was a great speech) because he doesn't know how Chandler and Monica got together.
We flashback to 3 years earlier when a very drunk Monica knocks on Chandler's hotelroom. After some talking Monica sort of jumps on Chandler.. and well we know the rest of the story.
However it turned out that Monica wasn't looking for Chandler she was looking for Joey (Yeah baby!). Chandler is not happy about this but after a conversation with Joey he sees that there some things in life are more important.
The Ross/Rachel/Ben story was also nice but not the best thing about this episode.