A gripe with Friends is that Joey and Phoebe would not be a have friends in reality, especially the later seasons.
Phoebe went from a slightly annoying hippy (can deal with that), to a complete bitch, strong in her beliefs but contradicts them constantly, selfish, when she upsets someone or puts her foot in, she doesn't care.
Instances are her telling Chandler that Monica had lunch with Richard, and putting Monica in the situation of having to reveal who she originally wanted to hook up with in London. In reality, she would be looking for some new friends.
As for Joey, he went from stupid with a good heart, but cable of some childlike wisdom. Too becoming so stupid, he would not be able to function at all in real life!