I actually liked books 4 and 5.
-cersei bumbling through power ( they actually went easy on her in the tv show) making mistake after mistake.
-jamie striking out on his own in the riverlands and failing out with cersei
- The Dorne plotline (done properly) and learning more about dorne.
- Finding out more about the iron islands, Victorian and Euron.
- Arya and the house of black and white. Taking that slower and more detail about her training ( not a rocky montage)
- tyrion travelling through essos, learning more about essos (though thank f**k for no penny)
- Bran beyond the wall
- jon taking command at the wall
Reek, Brienne, Dany and the jon connington stuff was Boring though.
But none of that would make good tv, and what did make the show was cut right back. You can't really fault the producers to much (apart from the god awful dorne shit).