This article is from the Friends FAQ, by Andy J. Williams AndyJW@dartmouth.edu with numerous contributions by others.
The episode guide which lists all the titles and gives plot synopses is a
separate document located at the Friends WWW Site and the Friends ftp site
[see 5.0]
As to why they all begin with "The One with..." ("TOW"):
JG: "When Marta & David & Jeff & I did 'Dream On', we used to spend a lot of
time thinking about titles, because they were on-screen at the top of each
episode. On "Friends", we decided that was a waste of time. We figured, why
not name each episode after the thing that people will ostensibly be talking
about around the water-cooler the next day?"
 
Continue to: