I'm rewatching with my wife (her first time through). We got to "Fly" last night. I warned her that this is a controversial episode as far as the quality. She absolutely loved it.
On my second viewing, I can't see how you people think this is a bad/boring episode. The character interaction and dialog is awesome. Possibly some of the funniest moments for Jesse in the entire series as well. That alone makes it an "entertaining" episode.
Then you have how heavily symbolic all their actions are within the episode, the microcosm of the lab reflecting the life path of Walt and Jesse.... damn... then it's also one of the most artistically rewarding episodes.
In this world of sin and sorrow there is always something to be thankful for; as for me, I rejoice that I am not a Republican.
- H. L. Mencken