This is by far the best sitcom I have ever watched. Having watched other immensely successful sitcoms like the office, I would ascertain the character development in friends is incredible. Most of the characters except Rachel, by the end of the show, did not change their nature from what it was at the beginning of the show. There were too many moments that were emotionally connected to me and that's where David and Marta Kaufmann have played their part. Monica has this finicky character which some of the audience might not like but her other aspects more than make for it.
Initially, Chandler's character looked the most comical during the first two seasons but after that Joey's character stood out to best in the series throwing up with instantaneous jokes that would tickle most of the bones in our body.
The scene where Joey is asked to describe the relationship between Monica and Chandler and add something about love, he consciously uses alliteration with loving....sharing.....giving....taking.... even after he inadvertently uses a better description of how they meant to him. That is the best scene of the series.
Go, check out the tidbits from IMDB which are interesting but don't read them before you watch the show as they contain spoilers.