The first film wasn't too bad, now we can look back through the prism of the second one. The 'fat Sam' storyline is awful, and the idea that Carrie would decide that Miranda's passing cynical comment to Big had ruined her wedding was beyond stupid, but it wasn't actively dreadful.
The second one gave us Liza Minelli singing Single Ladies, which was about five minutes in, and then needed to stop right there.