This show has been nothing short of awesome the first three seasons so I was pretty stoked my parents ordered up the fourth season on DVD to watch while I was visiting. We only made it through about half the season there and I finished up the rest at home. The first half actually has some bad episodes. None is as bad as the one about the fly, but some come close. Breaking Bad is about a good guy who makes meth to provide for his family so the first seasons focused on his dealings with rival gangs, etc., and featured quite a bit of violence. The first half of season 4 focuses more on his family and I don't care for them. His wife is annoying and his son is even more so because of his voice.
Fortunately, the second half of this season gets back to basics and the episodes feel like they could belong in seasons 1-3. There is plenty of violence, plenty of conflict and you can see the changes in Walt so you know season 5 is going to be good.
I highly recommend this season because of how it ends.